The first Witcher is kind of an acquired taste. The combat is a little janky, but the storyline, voice acting and old school RPG flavor to it is amazing. Hard to believe that it was built on a modified Neverwinter Nights Engine.
Witcher 2 is one of the best RPG's I've played. Especially cause it's almost two games. At the end of the first act you get to make a choice, and it's basically two enitrely serperate games after that. Different characters, stories, quests, everything. It's pretty amazing.
3 is supposed to be a lot more open world, Skyrim esque, and looks awesome.
Also, CDProjekt Red adds lots of DLC.. for free. They keep updating the games with awesome additions... for free. They recently added a HUGE mod pack, done by official designers on the game to add animations, combat tuning and tons of other stuff.
For free. You can usually get both games for like 5$ on any major sale.
http://www.youtube.com/watch?v=3kCGw_64Osc
There's the Witcher 2 trailer.