Diablo 3 - to buy or not to buy

well, d3 is definitely improving, it's worth a shot.

no no no

No. It's a really boring ARPG. It's just long hallways filled with monsters. TL2, PoE, Van Helsing all are better. PoE is free with way more replay value. TL2 has a shit ton of mods and you can pick it up for $5 when it's on sale. It's not worth it let alone you don't get all the content if you just buy the base game. PoE just had a free expansion added to the game which new skills, areas and a shit ton of new bosses.

I have spent many hours in DiabloIII, The Incredible Adventures of Van Helsing and Path Of Exile. Each games has good and bad things.
Diablo... i used to play in hardcore mode but i don't like hd 2.0, but i enjoyed most of the 500 hours i played it (in softcore you will be bored of the game much earlier).
POE, it's freeee... and have a dark style i like, but i havent been addicted as Diablo. (160 hours played)
Van Helsing. I liked it a lot, but after completing the game and playing the extra 'neverending' mode i prefer playing another game (140 hours played)

dont buy it, d3 sucks.

I picked it up on the half off sale to play with a bunch of friends. Really like how they've revamped it, but shame they took out the AH. I refused to purchase it after playing in Beta but really glad I gave it another shot after 2.0

They have a starter edition to try out. You can check the connection quality and basic gameplay if you like it.

After the patch 2.0 and Reaper of Souls, definitely to buy.

Wait for Dark Souls 2.

Play Path of Exile instead.

Diablo 3 turned out to be very good after a few major patches.. its different from the usual Diablo-Formular in many ways (good and bad ones alike).. RoS might shift it a bit closer to D2 again, but the major changes in gamedesign will affekt the base game too, even if you start without owning the addon, so I guess you shouldn´t worry about that. Start with the base game and when you like it and want more, buy RoS.

On the other hand, I´d advice you to try Path of Exile.. its Free2Play (and NOT Pay2Win, they have a very fair system and keep spending money absolutely optional, more like TF2).. it has a very D2-like feeling to it and some of the best gameplay-mechanics I´ve ever seen. As I mentioned before, I actually like Diablo 3, but Path of Exile is so much better than any other game of the genre..