A good gaming keyboard and/or mouse

for keyboard I suggest you a mechanical one with Cherry switches, Steelseries 6G v2 for example. Or Ducky is good too, but in my country Ducky are very rare :(, there are a lot other mechanicals with backlight, from Cooler Master, etc

If you want something with a great price tag - link
You may have to RMA mouse, because some of them are bad, but even if you factor in time=money. It's still very good value.

Microsoft SIDEWINDER X4 + Logitech G500

I use a Sharkoon Skiller keyboard and an Anker 8200 DPI mouse. Both clearly arn't top of the range, but since I haven't used the top products, I can safely say that ive had no problems with them whatsoever! The mouse is around £26 and the keyboard is £19.

I'd seriously consider a mechanical keyboard, one with cherry keys. They might appear overpriced but you will definitely not regret it. Mine is a QPAD MK-85 backlit mechanical keyboard with MX Brown keys which I picked on sale for just under £70. As for mouse I went with a Razer DeathAdder. Fan of both of these pieces of kit and both highly recommended. People like to hate on Razer but this mouse is a thing of beauty. Perfectly weighted, well placed side buttons and a nice grip, very comfortable to hold. You won't regret picking these too up :)

Logitech G400 (or equivalent)
CM Storm QuickFire Rapid (or equivalent)

No "gaming" bull****, just quality products for fair price.

This is the gaming mouse that I use. It has 5 profile settings on it so you can change your dpi on it at any time on the fly. You set the dpi to each profile individually and then you change between them at any time by pressing this minus and plus sign keys on the mouse near the wheel. The wheel is slow and clunky, but it's precise and it wouldn't slip and change someone when you don't want to. The 12 num keys on the side are incredibly helpful and have jumped my game up quite a few notches making playing tf2 competitively that much easier for me. Also you can adjust the weights in it to make it lighter or heavier, obviously. My only issue with it, is that's it's rather large and I have big hands and this thing is still kind of big for even me. Granted if you properly hold the mouse in the proper claw style. You have quite good control over it. When I use this thing correctly (remembering that it's just aiming and that this doesn't account for other naturally developed skills in the game) I can eat people alive with my accurate meatshots as scout. I feel like the mouse sacrifices speed for accuracy by a lot and even then it's not an incredibly accurate mouse. But it's a really great choice for a beginners gaming mouse. I feel like this mouse has helped me see what I need in a mouse. But aside from my bashing and making this mouse sound shitty. It's pretty good and I recommend checking it out at the very least. (Also it has flashy LED lights that have a glow effect. How can you say no? You just need to have a pretty mouse and you're already l33t :3 )

EVGA TORQ X10 Carbon or Razer DeathAdder. I'm using TORQ because I won at EVGA Anniversary Gaming Event last month and I think it's great.

I have a Tt eSports Challenger Pro which has a bunch of macro keys which I never use. I play mostly CSGO and I have nothing usefull to do with them in game. If I had the money I would easily change it for a mechanical one, like the one movac suggested with only difference to have backlight.
My Tt's fan it's nice for the summer though :P

I've got my Steelseries Kinzu V2 mouse for some time now and I like it. It's not anything extraordinary, still I can't complain. I didn't want a mouse that looks like a creepy transformer and I just didn't need any extra buttons as I don't use them (I know it after some years with more "advanced" yet cheaper mouse). So my Kinzu got only a dpi changing button and a wheel. :) But I guess I can just recommend Steelseries as a brand.