[Velocd]

Visuals are nice, but as mentioned by Mist, the atmosphere, interactivity, diverse and intelligent personality of the people within the community is what really crosses the line between a regular forum, and something exceptional.

Then it also boils down to what you're interested in and the target audience you're focused for. Yaxay.com may have a snazzy style, but I could really care less about graphix sites, there are such a huge crap load of them out there (usually all seeming to be prefixed with "pixel"), and I never really became interested in joining.

A good example of a really involving community (despite initially upon entering it seems like a graphix site) is such that of the one you moderate Mystis, Somethingleet.com. That community has a huge range of people with very intricate personalities, even though much of the language used around is typically vulgar, the people are intelligent (from those I have seen), and the discussions can get extremely involved (not to mention hilarious). Rarely do I see a forum that has threads with almost always replied to, never allowing one to slide down the list with zero replies.

Gamingforce.com, animeboards, and vBulletin.org are really the only other communities that I visit (other than my own ofcourse ), and enjoy the crowd around. The design is basic yet appealing on all of them (except maybe animeboards, which could use an upgrade).