BMW-Forums back in the days when I first joined and El Presidente had just started the "It"s Raining" thread was cool. BMWBeauty, Witeshark and I think M3Dude had just joined the same time as me. Everyone was helpful, down to earth and funny. BMW-Forums also had the best sections (video, lounge, etc...) and was a cool place to meet people. Now that forums got outta control and some good freq. members disapeared and new crappy members joined. The only negative was that alot of cats there are like 15 yrs old and have puberty crisis and shit.
BimmerForums- was way to much for me. I joined for a day and never went back....no one answered my question and it seems like everyone was into how much they knew.
DTMPower- visited for a day....Wasn't interested in putting flame thrower exhaust on my car or 25 inch rims....
Don't really have much time now to play around with the forums...but United Bimmer looks to have taken the best of BMW-forums and expand on that....again its really the personality of the members and people in the forums that most appeal to me! I could care less about what car you drive or how much you think you know.....