Help with finding a new computer (Updated with a bit more information)

What's your budget? Also, what kind of games do you plan to play on it? (ie, demanding AAA games or little casual things?)

Budget and scope of uses its intended for is the first thing to consider

As a quick rule of thumb, pay special attention to the graphics card performance. Many other desktop specs are pretty equal among new computers, but the graphics card is usually going to be the bottleneck and also account for up to one third of the total price. Use some hardware sites to look up how the card performs compared to the best ones and your personal requirements and preferences.

It helps to know what games you intend on playing for the duration you plan on owning the machine. Obviously your GPU will be the most important piece of hardware on your machine. Consider getting a machine with an SSD as a primary drive if budget allows. Do you have any techy friends that could help build you a machine? You will have more control over what goes into your machine. Just a thought.

For the start, I suggest you NEVER buy any branded PCs. Build it yourself or at least buy it from a website you can pick parts separately. Most websites build the PC themselves and test it after you buy all the parts.

Edit: I'm adding a list of GPUs and their relative performance from Reddit. You can use this as a guide for selecting a GPU.

View attached image.

If you want to build it yourself -> heres a pretty nice website that gives a good overview about prices and parts
http://www.logicalincrements.com/
if you just want to buy it, the main things to consider are, cpu, ram and graphiccard. also in any case you should use an ssd as main drive
all the best :)

If you're going to buy a prebuilt system then the three specs of main concern is the GPU, the CPU, and the RAM - in roughly that order. Pretty much every package you find will have one of these they excel at, and then not so great on one or both of the others to save money and make the price competitive. It doesn't matter if you have the best GPU in the world if the CPU can't handle it, for instance - but on the other hand most games are more reliant on Single Core speed and won't benefit greatly from a huge amount of cores so the top end CPUs are typically not necessary unless you're going for the last few percent of performance (which is costly).

So basically - first decide on the GPU range which is acceptable to you. This will depend heavily on what games you're interested in playing, whether you want to be ready for VR within the next few years, and so on. Read reviews. You don't care about brand here other than whether it's an AMD or nVidia, and while I tend to favor nVidia due to generally better experiences the performance is close in the top range of cards and it comes down to best performance for a given price. Find a good comparison site and look at the range you want, write down the general card models in that range, and then there's no reason to care who actually made the card.

Then consider your CPU. If you are aiming for high end GPUs then you'll need to check how good a CPU you need to not bottleneck it - just google the model numbers of the GPU and bottleneck CPU and so on and you'll find lots of discussions on it. How big a concern this is depends on how important those last few percent are to you, but also you don't want to "waste money" on a package that includes a GPU more powerful than you can actually use with the other hardware in the package...

Once you have a GPU range and a minimum CPU number to manage each level in that range, you can start finding your deals. Then you simply sort all acceptable deals by best RAM and cut off anything that offers less than whatever the most common offering is.

Next consider the remaining deals based on harddrive space and whether they have an SSD. SSDs are for anyone who has used them a necessity, but they also cost a bit so packages including them might be saving in other places... You do want plenty of harddrive space though, I'd say a terabyte is the bare minimum today - plus any potential SSD space.

Oh, and don't forget that you'll need a monitor as well, and keyboard/mouse. I wouldn't spend a lot of money here but if you're going to be playing a lot of fps games and you are really concerned with squeezing every bit of performance out you'll need a good monitor. That'll cost you a bit extra but I can't offer advice there since it's not something I've ever prioritized.

Good luck!

From the budget you've given and looking at prices online I'd say you're in the 'mid-range' market.
The cpu doesn't need to be the fastest on a mid range rig and you should rather scale back the CPU in favour of a better GPU if the choice has to be made. It doesn't even need to be a current gen CPU, as the differences in performance are only going to be noticeable at the very top end of graphical output. So shop around a bit and see if you can't find a better price on an i5 from the last gen, as sometimes shops will clear out the older stock for cheaper. So an i5-6500 or i5-7400 will probably be more than fine. I'm running on an i7-2600, which does need an upgrade as it's five years old, but even with my AMD 480, I find the cpu doesn't ever work too hard. So next year I'll probably upgrade, but only because I want to, not because I need to.
For the GPU, you should aim for an AMD 580 or a Nvidia 1060, and the option with more Vram, to help extend the lifespan of the card. Both brands have their advantages, but unless you want to get into frame specific statistics, game by game, either card will no doubt happily push out enough frames for you to enjoy in whatever games you play.
All the other parts will flow on from what you spend on your GPU and CPU.
Next on the priority list should probably be 16 gigs of ram, as there are more games coming out that rely on that. 8 gigs will pass for most games, but rather get 16 and then you won't have to think about it later on.
The motherboard won't come into play so much in a mid-range rig, so don't waste a lot of money on that unless you want to. Anything from a decent brand will probably be fine, and you can always upgrade later if you really need.
A solid state drive is fantastic, but it can also be added later very easily, so to get you up and running, rather spend a bit less on a 2 terabyte disc based drive and add a SSD when you find one on a good special one day.
The power supply should be around 500w.
The chassis, aim for something that's got a bit of room, just to help air flow and ease of wiring.
Keyboard and mouse - something cheap at first, you can always upgrade later

Have a look on PC Master race subreddit, they have a dedicated page that lists proposed builds with explanation what they are capable of:
https://www.reddit.com/r/PCMasterRace/wiki/builds

It also has a FAQ section and links to other subreddits where you can seek help regarding building a PC:
https://www.reddit.com/r/PCMasterRaceBuilds
https://www.reddit.com/r/BuildAPC
https://www.reddit.com/r/PCMasterRace

If you decide to go with an Intel CPU, the next generation of CPUs should be released next month and I think there will be a decent performance gain. You can go with the latest for the best performance or if you are looking for a good deal on a last gen CPU, there will probably be sales between now and then if stores try to unload their remaining stock before the new release. I think the best performance per dollar would be to buy the newest generation because I don't think the last gen sales will be that large.

Currently AMD's new Ryzen CPUs provide more performance per dollar, but we will have to wait till next month to see how the new Intel CPUs compare.

PC Case Gear have some decent pre-built systems that are well suited to gaming, at a number of different price points.
https://www.pccasegear.com/category/1411/systems

If you're intending/willing to assemble the PC yourself then you might save a bit more money since you can apportion more of your budget towards the parts that matter more to you. For example, when I built a PC recently I spent a decent amount on fans, a decent CPU cooler and solid state hard drives because I like my computers to be dead silent. Normally prebuilt systems would strike some sort of balance between performance and cost, and noise is not a factor.

So you said it was also for art. What software do you use and do you have several heavy software opened at the same time?
If you use Adobe software or do 3D modeling I suggest you prioritize the CPU (go for an i7, not under) over the graphics card.
Also as an artist you should invest on a screen with very good colors. I have an AOC I2481FXH and it's perfect for that matter (also it's very elegant compared to most "gaming" monitors).

There's plenty of good advice in the previous comments but I'll insist that you should build your PC yourself. That's how you'll be able to have something that really fits your needs.