I've only ordered two vanillas: Capellas Vanilla Custard, and TPA Bavarian Cream.
The Vanilla Custard bothered my airways, for some reason, but it did taste good to me. It's not unusual for me to find something that I'm sensitive to in e-liquids, so I pushed on.
I now have trouble stopping myself from adding some amount of the Bavarian cream to any batch that I make. Seriously, unless I'm making something that vanilla just doesn't sound good with, I add at least a couple of drops. Good stuff.