In general?
RTS: - RTS have gotten very far in the last few years. Company of Heroes, which is a great World war 2 RTS is one of the best there is. You should really try this demo. The expansion recently came out aswell.
A personal favorite for me is World in Conflict. Absolutely amazing game. Amazing visuels. Some people say it's the most graphic intensive game there is on the marked, besides Crysis!
If you are a hardcore RTS player. If you really know all the ropes and like it hard with micro management and like the idea of using dual monitors for better tactical strategy, check out the spirituel successor to TA, Supreme Commander.
Another one of my personal favorites is Medieval Total War 2, and this is the game I would recommend over all the others. The game is a mixture of a war RTS and a table top risk/stratego game. It might sound strange, and in a way it is, but its great. The goal is to take over the world. You start the game around year 1200, and then you play as a faction. The english, the french or some other. And then you you fight for power. Its awesome. You play through alternative history being witness to stuff like the black plauge, the crusades in the holy lands, the introduction of gun powder, discovery of the new world, attack of Hannibal on the roman empire, etc...
RPG: Back in 2006, Elder Scrolls: Oblivion made a big splash. This much more straight forward, open ended action First person RPG, boosted great graphics. Its a game that is worthy having in your collection. While the main story is nothing special and the fighting is a bit shallow, it does not have many of the game breaking bugs of its predecessors(Arena, Daggerfall, Morrowind). Its fun just going off into the world and do random stuff and quests and help people.
Another recent game, is called The Witcher, which is based on some novels by an acclaimed Polish fantasy writer. You play in a fictional fantasy land, as a monster slayer called Witcher boosting large swords and white hair. The combat is quite strange, and it will seperate folk. I recommend the game highly due to its interesting mechanics. But its not quite the wake up call for Action RPGs, that we had hoped it would be. There still is no single player action RPG like Diablo 2.
And speaking of Diablo 2, you might also want to try Hellgate London. The demo at least. Some of Diablos creators created this post apocalyptic re-take on diablo, set in london. Many people where dissapointed by this game, but they have updated it constantly since last year, so maybe its better now.
And while we are speaking of Diablo creators, another bunch of ex-blizzard veterans formed their own company back in 00, called Arenanet. They released a game a few years back called Guild Wars. It got alot of attention as the press labeled it as "the free MMORPG".
Besides World of Warcraft(WoW) which came out almost a year before it, GW is the only "real" western MMO success story. It just passed the 5 million sold mark. Though this is only half of WoWs current Subscriber base.
I recommend that you download free trials for both WoW and Guild Wars. Fileplanet.com is a good place to create a free account.
While you are at it, you should also take a look of the free trials for the following: Lord of the Rings Online, Tabula Rasa, EVE and Everquest 2.
FPS: Alot of FPS have been released lately. Some of the more interesting ones, includes STALKER. An open world FPS with light RPG elements.
Also there is Bioshock. Not quite System Shock 3, in my mind, but still an excellent game boosting impressive animations and a believeable world. Believe me when I say, that it is worthy of your attention. It takes place in the early 60s, where your plane crashes. You find a lighthouse. You go into it. And suddenly you find yourself in an abandoned(not really) underwater utopia that went wrong. people started buthering each other. Now your stuck in hell under water with no way to get up. Its an interesting and different game. It recieved alot of praise for its art style. "Art Deco". It looks like something from ages past. It got a look to it you wont find in other games.
You mentioned that you had BF2, and while it may dissapoint you, I would say that BF2 for the PC is still one of the best things there is. If you can crank up the visuals there is few things better than a 32 vs 32 fight. You might wanna try Battlefield 2142, a BF2 in space. Some people love it, others hate it. Quite like it Was with Battlefield Vietnam, before 2 was released!
Unreal Tournament 3, also recently came out. It seemed to drown in the wake of the others. Even the PC version of Unreals own Gears of War, which you should also check out.
Crysis of course. The most beautiful game in the world. Bar none. Nothing can touch it. Its far Cry on fire. Crytek outdid themselfs. If you got a beefy machine, and I mean, REAL BEEFY, then go ahead.
I also recommend trying
Call of Duty 4 and Orange Box are obvious recommendations too.
Quake Wars.
I could go on, but I would really recommend getting Orange Box. You will Get Half-Life 2, Half-Life 2: Episode 1, and Episode 2, Portal(which is mindblowingly amazing) and Team Fortress 2! 5 Games in 1. And they are all of the highest quality.
Regardless you should have Steam on your computer. There is this game particularly of mine, that is amazing, called AudioSurf.
In AudioSurf, you "ride" your own MP3 songs. You control a ship, in wipeout/F-Zero style, but the track of the levels is created by the beat of your own MP3 songs that is playing in the background.
Its an amazing game. You have to try it, and tell all your friends about it. Its so much fun.
Steam has alot of great little products like that.
A good place to download demos for free is fileplanet.com (yes you can create a free account. they just try to make you buy a full account) and filefront.com There are demos for almost all the games I highlighted(except for Oblivion).
What to look forward to in 2008: 2007 was amazing for PC games, but 08 looks great. People are really itching for Starcraft 2! It showed when over 50,000 South Koreans attended for the games revealing.:O Pretty scay. Starcraft is religion to alot of people, hehe.
Also worth talking about, is of course Sim, creator Will Wrights "Spore". It will be one to watch.
And finally, after 10 years in the making, it finally seems that Duke Nukem Forever will be released this year. But then again... Its Duke Nukem!
Also, a prequel to STALKER is coming out this year, called STALKER: CLear Sky. The developers promises big improvements to the core gameplay.
Also, this year but it might not make it until next year, is Guild Wars 2 aswell as the next WoW expansion, called Wrath of the Lich King, boosting the cap up to level 80.
As for other MMOs this year, alot of people are waiting for Age of Conan, which is coming out soon, and Warhammer Online! These two games have massive hype and big followings.
Left4Dead is also a big release for Steam. Still running on source, this is a rare one for PC indeed. An online Co-op zombie adventure, where you have to play as either a few survivors or as the actual zombies themselfs. This should be really good.
Battlefield Heroes is coming out this summer, and it will be completely free, so look forward to that aswell.