I've been an AiV fan since I first started vaping in 2012. In fact "White Rabbit" was my first venture into "premium e-liquids", and I've been hooked on AiV ever since!
As for your choices, here are my opinions, but taste is VERY subjective, so you may find them to be completely different...
1.) Frost Blossom--I'm not a fan of menthol or mint vapes, but as they go, this one is pretty good. Smooth and cool, without the "smacked in the face with a bag of frozen mint leaves" sensation like some menthol vapes...
2.) Twas Brillig--my ADV. I go through this stuff like nobody's business. I LOVE this stuff. Fruity without being candy-like. Sweet without being cloying. And a hint of bakery flavor without tasting like stale bread. Blackberry Crumble in a vape--Yummmmmmm....
3.) Fifteen Foot Falls--an interesting flavor. One of the few AiV flavors that I find too sweet and I have a MASSIVE sweet-tooth. It's good for what it is, and if you like marshmallow and coconut flavors, this one will hit the spot!
4.) April Moon--Interesting. Hard to describe. Exotic fruits, and a dark richness that I can't quite nail down, but the juice itself is rather light-flavored. I go through this pretty fast too, but it's not an ADV for me--more like a "weekend treat" vape.
5.) Mang-Ri-la--a new flavor, and a close second for me as far as my all-time favorite AiV juice. The mango flavor is spot-on, and it's sweet and complex and rich without being overpowering.
You'll hear a lot of people saying they don't like AiV because their flavors are "too subtle" or that they "don't have any flavor if you vape them at high watts". And I suppose, this is somewhat true. It has been my experience that most AiV jucies ARE complex, and filled with subtle layers of flavor, and require you to actually WORK at figuring them out, if you are the kind of person who wants to be able to describe the flavors.
And form my experience, they work best in attys or other devices that are in the 1.2-2.0ohm range, and at relatively low power--from 6.5-9.0 watts. Anything above about 10 watts, and in my experience the flavors do seem to just sort of burn off. I think this is because they use very complex recipes to make their flavors, and the simple fact is that when you have 8 or 10 ingredients in a juice, no one flavor is going to be much more than about 5%, so at higher power, many of these subtle, light flavors--in small percentages--just won't hold up to the heat.
For me, this is not a problem. I am a low-watt vaper. I rarely feel teh need to go above 9 watts, and generally vape at between 7 and 8 watts. I don't do sub-ohm builds, and I use regulated devices almost exclusively. I've found my "happy spot" and I have no need to prove anything to anyone by blowing huge clouds or risking facial disfigurement with impossibly low resistance builds... ;-)
Just give me rich, complex, yummy flavor, and high VG in the mix for respectable vapor, and I'm a happy camper.
So anyway, that's my opinion on AiV. Good luck, and I hope you enjoy their juice!