Admin note: Guys, Negative Sun requested that you not just list what your Top 5 PC games are, but to explain your choices as well. When replying, please read the first post, as a disturbing number of you have just gone with the laundry list approach. I'll give you until the end of the week to fix them up, after that, if they're still just listings, they will be summarily deleted.
5. Vampire the Masquerade: Bloodlines
Many thanks to stoffe for introducing me (and several others) to this sinfully delightful game. Being a bloodsucking creature of the night has never been so much fun before. I loved the many different options the game gave you with respect to character classes and storyline progression. It was also pretty awesome that they had a character named after me in the game as well. :D The soundtrack is kicking rad, with stuff from Lacuna Coil, Chiasm and the Genitorturers, as well as some ambient and throbbing original tunes from composer Rik Schaffer. Definitely one of the better games I've had the pleasure of playing recently.
4. Star Wars: Battlefront
This game is on here for sentimental reasons, as I had a crapload of fun playing Battlefront online with friends. Sure, the gameplay was a little funky and quite buggy at times, but there was nothing like rocketing your buddy over the tall treehouses on Kashyyyk, gunning them down with tanks on Geonosis or vaping them in the cockpit of a starfighter. I was actually quite thankful that playable Jedi were not included in this game, since that would have made the land battles pretty sucky and unbalanced.
3. Sid Meier's Civilization II
I cannot count how many hours I devoted to this game over the course of my gaming lifetime. Very deep and infinitely addictive, this damn game had me spending entire days on it. I think I must've gone through each different civilization at least twice and each scenario once, not even counting all the various custom scenarios downloaded from the Internet. It was either this or its descendant Alpha Centauri going on my list, but CivII's nostalgic value won out. Definitely an old school game I love revisiting again and again.
2. Guild Wars [Prophecies + Factions + Nightfall]
I haven't been playing much GW lately (damn job :/) but I've still logged more than my fair share of hours into this deceptively complex CORPG. This was my first massively multiplayer online game and I'm quite glad I chose it. The biggest initial selling factor was the free online play, since I don't believe in paying for a game more than once. As I got more and more into it, the skill-based aspect of the gameplay really made me warm up to it. Instead of relying on grinding for XP to become uber-1337 high level, GW forces you to become proficient at using the skills at your disposal by enforcing a level 20 cap. It was daunting at first, especially with most of the baddies being higher level than me, but I was able to find a wonderful guild that helped me through even the roughest of places. And I don't have to sell my soul and life to play it either, since there are no monthly fees and I can pick it up and drop it as my real life dictates.
1. Star Wars: TIE Fighter
My top spot really was no contest, as I practically grew up on TIE Fighter. My first ever space sim, I spent many hours in my youth vaping Rebel starfighters for the glory of the Empire. I loved that it wasn't just about shooting everything dead, but also protecting mission-critical craft and accomplishing certain objectives. And there really is nothing like flying by the seat of your pants in what basically amounts to a fighter made of cardboard and tinfoil. It's still my favorite space sim to this day.