Hmm...I suppose I'll suggest a few games from each genre I enjoyed.
Point & Click:
1. Indiana Jones and the Fate of Atlantis (As good/ better than the films)
2. Gemini Rue (Excellent cyberpunk noir)
3. Full Throttle (Just watch the trailer on youtube...Really does it justice)
4. Lost Horizon (Much like an updated Indy, amazing artwork, quite fun)
Platformers:
1. Another World (Stunningly original, immersive, cinematic side-scroller)
2. Treasure Adventure Game (A free, fun little metroidvania kinda game)
3. Rochard (Fun 80's styled Sci-fi sidescroller/puzzler with an awesome soundtrack)
4. Journey (An ethereal experience, very relaxing)
First Person Perspective:
1. Metro 2033, and sequel Last Light (Amazingly atmospheric, story driven Horror/Survival/FPS)
2. The Thief Trilogy (Basically invented the Stealth Genre as we know it. Graphically dated, but amazing gameplay and story)
3. Penumbra: Overture (Deeply unnerving and scary Survival Horror)
4. Realms of the Haunting (Original FPS combined with Point & Clickery, and actually
GOOD FMV cut-scenes)
RPG's
1. The Witcher Series (Starts off slow, but becomes rather engrossing. Recommended to mod the combat)
2. Vagrant Story (a JRPG with an interesting combat mechanic, cool cut-scenes and story)
3. Jade Empire & Anachronox (Haven't played them, but look quite promising)
4. Deus Ex (But, Surely you've played this already...Right?!)
Flight Sim:
1. Pretty much the entire Wing Commander Series (Very fun WWII in space vibe, really benefits from a Joystick)
2. IL-2 Sturmovik (Check out Jefmajor's Let's Play of it, stunningly realistic WWII fighter pilot sim)
Open World:
1. Mafia (Splendid recreation of 1930's America, interesting characters and world)
2. Shenmue (Nothing like it before or since. takes 'open world' to a whole new level)
3. Sleeping Dogs (Haven't played much of it, but it seems pretty fun, and exploring China is very neat)
Stratagy:
1. Silent Storm S2 (Basically X-Com in WWII)
2. Jagged Alliance 2 (Turn based, squad tactical country liberating action!)
3. Rome: Total War (Massive real time ancient battles of a grand scale, very moddable!)
4. As others have said, Valkyria Chronicles
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Well, That's about all I can think of for now. Hopefully you'll enjoy something on that list.
