A new branch of a game store just opened between my work and home and they have game nights on a day I'd be able to attend. I'm planning on taking Sentinels, but I have one concern. Do you think I should take everything, or just take a subset of the available decks in one box to not scare people off the game (at least for the first couple weeks)?
I take everything, although some of that is because of how I have it stored.
What I also do is lay out a game - because I usually pitch it around the Avengers, it's usually against Omnitron or Voss, laying out Legacy, Wraith, Tempest, Ra, KNYFE, Parse, Bunker, and Haka for people to pick from. Lay out the environment decks for Insula Primalis, Atlantis, and Mars; let the players come to an agreement. My experience is that they usually pick Mars and pick Insula Primalis when they don't.
I usually do those heros (along with chrono ranger), have the villains be Omnitron, Baron, or Ambuscade, and have the Time Cataclysm, Insula Primalis, The Block, or Wagner
I take everything and usually encourage people just to choose whatever hero they think sounds the most cool to them. I have the box arranged in rough order of complexity and give a brief overview of how differently a few of the decks play, e.g. this one is straight up damage dealing, this one has lots of ping damage that combos up into bigger things, here's another that does a lot of deck manipulation, etc. One guy at my club went straight for Absolute Zero as his first hero as he loved the concept and wasn't put off by it being a more obtuse deck than some of the others. Other people just want to pick up Knyfe or Ra and deal big lumps of damage, but the point is they know what they are getting into and can enjoy the concept of the hero they have chosen regardless of how accessible the deck may be.
The only thing that I usually govern is villain and environment; I like to start new payers on Voss or Dawn as they are immediately recognisible types of supervillain, have plenty of minions to target, and both throw curve balls at you every now and then. I think they highlight the fact the game is more than just a straight beat down against the clock, and there's a good chance you could either lose or only scrape through with some incaps to prove that it isn't a walkover (which is a complaint I've heard from first timers after playing Blade or Ambuscade). Both villains can also run for a decent number of rounds which allows people to see a good part of their decks and to get a good feel for the potential in the game.
But yes, I recommend taking everything. The people who like it will be excited at the prospect of exploring all the things in the second and, who knows, maybe third or fourth game of the night.
The Ennead is also a good starting villain, beccause like you said with voss, there is always somebody to beat on. Not to mention they aren't too high maintenence, but still show the creativity of some of the villains
All the symbol triggers are pretty fiddly though. I had a lot of trouble keeping all that straight when I first played them, and I wasn't inexperienced.