http://www.therebirth.net/
Closest to live-like vanilla wow you'll find. Not sure what the pop is like there any more, it didn't pull numbers like Molten due to classic 1x rates and no donor rewards. But the owner/dev is awesome and the server was always stable.
Scriptcraft was fun while it lasted. Not quite as accurate in terms of scripting, but the pop was 1k+ for awhile. Tons of BG's all day + world PVP (AQ gate opening anyone?).
But then the owner turned out to be a money-grubbing bipolar asshat that shut it down, started it back up after taking a ton of donations, then shut it down again.
No others were worth playing on imo.