This question is impossible to answer, because Armada has so many great skis. Picking one is like picking who is the hottest Victoria Secret Angel, it's a matter of personal preference. That's why I have three Armada skis, The Alpha 1, JJ, and ARG. The ARG is the best pow ski ever, and it's very versatile for a ski with a 133mm waist. The JJ is amazing at everything, from Utah pow to east coast ice to East coat rock hard landings to nose butters/presses. The Alpha 1 makes spins, flips, spins on, k-feds, spins out, and butters incredibly easy thanks to the elf shoe and rocker. I personally love elf shoe and rocker because the low turn radius, increased switch ability, powder ability, but still having down camber to handle groomers and most off all low swing weight. Also they do ski "short", I am 5'9" 135 lbs and I ski 185 JJs and Args, and 176 Alpha 1s.
Arg-Best pow ski, the ski has 24 inches of rocker in the tip, 28 inches of down camber, and 20 inches of tail rocker. The rocker is not nearly as abrupt as the Hellbents, Ep Pro, or even the JJ. It rises slowly and makes the ski slay pow but still be able to get around the mt better than any pow ski on the market. The ski is really stiff which I thought I would hate because I thought a pow ski wanted to be buttery soft(like the ep pro, bentchetler, and hellbents), but I was completely wrong. The stiffness allow you to charge so much harder, increased switch ability and landings, and makes butters not as hard as one might think(don't compare buttering on groomed snow to buttering in pow). The length of ski touching the snow is about 72cm!!!
JJ- Most versatile out of the Armada fleet. They have low swing weight, and slay park for a ski with a 115 waist. They rip groomers and have a super low turn radius(185-14m 175-12m) which is useful when shutting down speed coming into a pillow line, cliff, or in tight east coast trees. The rocker is almost identical(if not exactly the same) as the bentchetler(20cm in, 20mm up) and is perfect for the JJ. It makes it float in pow(not as well as the ARGs), but with more down camber than the ARG it holds an edge on ice and groomers.
Many people don't know what Armada park ski to get, and I will try to help because I have owned the T-Hall, AR6, and Alpha 1. I have skied the Halo(last year when it was called the Alpha 2) and AR7.
AR7- If you are used to trad. park skis this is probably the best choice for you. It's everything you would want in park ski. They are a little stiffer than the average park ski.
Pipe cleaner- A little softer than the AR7(barely and I couldn't notice it). This ski is not just a pipe ski, its more of an AR7 with a race base.
T-Hall- This ski is not comparable to any other ski on the market. The reason that a lot of the Armada team ski this is because it allows you to do things that others simply don't. The middle(where the regular sidewall is) is stiff and holds an edge well. The tips and tails are incredibly soft(more so than the Anthems) and make butters and presses easy. And you do not have to load the tips as much when buttering.
Halo- This ski is good for a park skier that is not that agressive(dont think that agressive skiers cant ski this). The flex is softer than the Alpha 1 throughout, but the biggest difference to me is the base. The base is the same as the AR7, its not slow but its not close to an Alpha 1s race base.
Alpha 1- This ski is my personal favorite because it's made for more agressive skiers. The race base is super quick if waxed, and if you dont wax its still faster than the Halo's base. The flex pattern is the same as the AR7 and is nicer if stomping bigger jumps, and bigger rotations. The alpha 1 does have a little bit of rocker in the tip and tail and elf shoe, and it makes spins a lot easier and butters as well. My friend calls it butter shoe tech. This ski is not for a new park skier, but you will never be laying on the ground looking at your skis wondering why you didn't stomp a trick. The better you are as a skier the better the Alpha 1 is for you. The extra $50 is more than worth it over the Halo, but the graphics are not as good.
The one complaint I have with elf shoe is the durability, because a lot stress is put on the elf shoe. The ARG and JJ are versatile but not that durable so be careful if you hit a ton of rails, but are more than enough if you like to have the occasional rail session.
I am a horrible speller and I know it. If you have any questions feel free to ask.