I've seen some great VB4 and VB5 styles, you just have to look really hard for them, Exaltic do some great VB4 styles that are way beyond a default tweak or two.
Them problem is you have to be willing to pay, and by that I don't mean $30 -$50, I mean start at $450 and you can get a really different custom style, it's all down to price really.
Personally I've seen really terrible themes on really successful forums, so a custom theme is no guarantee of a successful forum.
http://www.thefootballforum.net/
http://www.footballforums.net/forums/
Both of those are on page one of google for "football forum" and one is the default with no customisation at all !