Tasty Vapor has some of the best dessert liquids (with "in your face" flavor) and is quite affordable -- especially if you order flavors that are on special (they usually have 4 on special per week)...better yet, once you find flavors you like, if you order their 2 or 4 ounce doublers and add your own nicotine, it's ridiculously inexpensive. they have excellent, consistent quality, fast shipping, and great customer service.
if you're looking for tobacco blends, Backwoods Brew has some of the best, as well as a few excellent, subtle, non-tobacco selections. they have decent/average prices, and their shipping is good. the only drawback is that they are often out of stock.