I'm currently playing through Half-Life 2 (again). This time, I'm using the Cinematic Mod along side the core game and the landscapes are beautiful! I have most of the custom NPC models off, since they look either seductive or awkwardly animated. Though, my only complaints are:
1) New zombie model - It isn't faithful by any means to the original game.
2) It's easy as hell to sequence break in Highway 17 and Sand Traps by climbing the sloped ledges.
3) I stole Father Grigori's rifle, so now I need to use all my .357 ammo before I can use the AR2 (This glitch exists in the original game, so it may not count as a direct complaint about the mod itself)
And 4) New headcrab sfx.
Other than that, it feels like a brand new game!
------------------------------------------------------------------------
I'm also playing:
Pokemon X
Majora's Mask
Kerbal Space Program (on and off)
Team Fortress 2