I only tried a few other distros, and most of them were Debian-based. Here are the top 10 reasons for which I enjoy using Debian:
Read it here
Community is great, and I'm talking about both the forums at forums.debian.net and the official #debian channel on OFTC. Debian still has a channel on Freenode, which actually has more users than the official one (an average of 800 compared to 350 on OFTC).
LE: I almost forgot: mailing lists are another way of getting responses to Debian problems and discuss any aspect related to it.