Good, games to play on pc?

That's a hard question honestly lol, but I'll do my best. You have to decide how you define "favorite". I would say it comes down to hours logged per game and replayability. Games that you can replay over and over and still have a fun experience is what I truly call a favorite game.

Single Player

1. Elder Scrolls 3 - Morrowind - RPG
2. Elder Scrolls 5 - Skyrim - RPG
3. Elder Scrolls 4 - Oblivion - RPG
4. Alice Madness Returns - Action/Adventure
5. American McGee's Alice - Action/Adventure
6. Fallout 3 - RPG
7. Fallout New Vegas - RPG
8. Bioshock - FPS
9. Bioshock Infinite - FPS
10. Half-Life Source - FPS

Multiplayer

1. Heroes of Newerth - MOBA
2. Battlefield Bad Company 2 - FPS
3. Battlefield 3 - FPS
4. Guild Wars - MMORPG
5. Guild Wars 2 - MMORPG
6. DOTA 2 - MOBA
7. WarCraft 3 - RTS
8. StarCraft 2 - RTS

At this time, this is what I'm thinking for me.
 
1. Unreal Tournament series 99, 2004, UT3 (Where I started gaming, and spent the most time)
2. Dirt 1,2,3. (2 is my fav)
3. Race driver GRID 1 and 2
4. Far Cry 3
5. BF3
6. BF2
7. Transformers War For Cybertron/Fall of Cybertron. (Console ports but still great stories)
8. Original Gears of War for PC (WAY better than the console version IMO)
9. Lost planet Colonies (I loved beating up on 360 players from my PC 😛 )
10. Final Fantasy Games. (all except MMO FF)

PS. I forgot the Elder Scroll games. Morrowind, Oblivion, and Skyrim. Also Fallout 3 was pretty sweet as well. Most of the Need for speed games as well (Underground 2 is my Favorite NFS). Damn every time I update the post I think of more games. haha, :)