BasilZero gave it a good go, but my number 30 is:
30. Neverwinter Nights + Expansions Shadows of Undrentide & Hordes of the Underdark (PC)
I unfortunately didn't get into Baldurs Gate when it came out, so this was my first real foray into Western RPGs, D&D and also my first Bioware game. From the start I loved it. The story was brilliant starting with a plague in Neverwinter, multiple problems aflicting the city eventually leading to the betrayal of Aribeth. The expansions were also good adding in prestige classes as well as new stories. The multiplayer component was also well made and aided by mods created using the toolset. I played this co-op with my partner which worked very well, but someone also released a mod using the toolset that effectively recreated the game Everquest in the Neverwinter Nights engine! Awesome 
