I don't like Blizzard much anymore. I liked WarCraft 2 and 3, and Diablo 1 and 2 (liked is a bit of a strong word for Diablo 1 and 2, though... 'twas more addicting than fun). Nice gameplay, good for LAN parties, and a decent hacker culture on all of them. In fact, the excellent map editors in StarCraft and WarCraft 3 were inspired by some hacker-made Warcraft 2 map editors.

Now? Blizzard's doing all they can to control the whole experience. No LAN capabilities, shameful treatment of the bnetd folks, and others that have been mentioned here. Contrast to id games who open source their engines and invite folks to build on them.