Alice in Vapeland. They usually open at 11PM on Tuesday night, or midnight Wednesday morning and are only open for maybe 12 hours or so. Then you have to wait about 2 weeks for the juice, which is why I didn't order from them for so long, but WOW! Their juices are definitely worth it. I recommend White Rabbit, Twas Brillig, Zombie Apocalypse, Lemon Loves Cake, Mystic Mandalime, A Quiet Morning, Pun'kin Tumble & Bandersnatch (but really, you can't go wrong if you order the A Little Bit of Everything sampler pack).
If you like VG base, I recommend Velvet Cloud Vapor. If you want tobacco, their Blue Beard, Ice Beard, White Beard & Caramel Tobacco are all really good (but need to steep about two weeks for the flavors to blend really well). I also like Harvest Berry, Mewlew's Magic, Campfire, Monkey Business & Nightshift.
Roar Vapor for Truth Serum (coconut/pear) & Antidote (I think it's blueberry lemonade). A lot of people rave about many of their flavors, but I've only tried about 8 and those are the only 2 I can remember right now.
I recommend Mt Baker Vapor, but no specific flavors. They have pretty good juice at a really low price, and it's very customizable. I personally really like Rockstar (though I think when I re-order I'll have them add one extra shot of flavor) and Sticky Bun so far.