There are a LOT of flavors which are great right as soon as you get it. For example, Mount Baker Vapor's "Mudslide", "Cinnamon Roll", "America" and a number of others are perfect just as soon as you get them. However, with time the tastes will get a bit more ... what's a good word? Interesting? I can tell you one thing, if you keep Cinnamon Roll uncapped for a few days, then let it sit for two weeks, you'll notice a dramatic difference in color and taste. You get more of a dough flavor with vanilla after a few weeks, while when you first open it and have a go, it's more cinnamon. The same goes with their "Green Apple". Right out of the bottle, you can vape it, but give it a few weeks it turns a sort of green color and the taste is much better.
I have two bottles from Alice in Vapeland which I'd initially liked, then sort of lost interest in quickly; Punkin' Tumble and Bandersnatch. At first, perhaps 5 days after I got them, I dripped then used in my ProTank and I liked them. Went back a week later, and it was very "meh". On a whim, I tried them both a few days ago, and it was a totally different story. Much more banana in the Bandersnatch, and I could really taste the pumpkin in the Tumble. A few of my other regular vapes are from Mom n' Pop (Pchela's Poison for one), and as soon as I get them, I uncap and let them sit in a small bowl of boiling water, poured in as high as it can go without tipping the bottle. I repeat that 3-4 times, let it sit over night, and bam. Ready to go. But if I can be patient and just let them sit on their own, about 2 weeks it's much, much darker and the flavor is far better.
Yeah, I'm impatient, and HATE having to wait to use my new juices

But you know, much as I used to be skeptical, it's true. They really do want some time to sit. I don't know if it's the nicotine settling in to the juice, if it's the alcohol evaporating or what it is, but you're so much better off letting it sit for a while.
Hmmmm.... I didn't expect another layer of complexity to trying to find new juice's. Oh well I guess I will figure it out as I go along. Thanks for the info everyone.