Was wondering the same thing myself, decided just go with 4.0. If you are going to go to it eventually might as well save yourself headaches in upgrading and then learning all the new things it offers.

Definitely 3.8, as Paul M said, in case you do not want to modify your forums for time being (unless your mods can be easily ported to vB4). Otherwise, go with vB4 - but even in that case, I'd wait a bit before modifying styles and templates excessively.

vB3.x

That can be done with a test board. For the live version, I'd stick with the most recent stable version, which is 3.8.4. It'll take a while before most of the mods support vB 4.0. With 3.8.4 they're a sure thing.

Just use 4.0 if it's a new board.

Gold will be released before the end of the month, so if i had a new board, i would go for v4.

I've thought about this subject and well, since vB 4.0 Gold is slated to be out in a couple of weeks I'd opt for 4.0 too. The transition from Beta 4 to RC1 was quick. I changed my original position. :D

Four.

For some things, I'm an early adopter, but for scripts, I'm definitely not, so I'll say 3.8.

Are the nav bar buttons on 4.0 gonna stay that bad? They look so ugly and don't even fit the bar itself-too tall. If so, I'm never upgrading to this. Also what's with the header image? It looks chopped off at both its and look totally unfinished.