I really like original mods. Running and shooting got a bit of tiring for me.
Some games I like:
• Beyond Good and Evil
• Gothic 1, 2 + NdR
• Psychonauts
• Arx Fatalis
• Penumbra
• Enemy Territory
• Clive Barker's Undying
• Aquaria
• Thief: Deadly Shadows
• Startopia
• Call of Cthulhu: Dark Corners of the Earth
• Evil Twin: Cyprien's Journey
• Wario Land

My system:
• AMD Phenom 9550 Quad-Core
• 4GB DDR2 RAM
• ATI Radeon HD4850
• 320GB HD