Sometimes, everything about a card just fits together perfectly. The function, the art, and the flavor text unite to create something particularly memorable. While I don't actually have a favorite hero, villain, or environment, there are several cards that simply stand above the rest for me.
Into the Stratosphere- It's useful, the art is great, and it very clearly simulates its effect mechanically. Tempest has one hell of a pitching arm.
Cryo Bot- He's difficult to use effectively, but he has the potential to be amazingly useful, just like the real thing. Also, you know, Unity. Just... Unity.
Imbued Vitality- I love the implication that not only does Wraith bring her hairdryer-device with her wherever she goes, it's a HUGE NERD.
Lost Child- Spite is an awesome villain. He'd be a pretty interesting episode of Law & Order SVU, that's for sure.
Vigilance- This card pretty well encapsulates what the Iron Legacy timeline is like. I'm glad I don't live there.
I'm rather a fan of Sucker Punch, because of Tachyon's tongue-out concentrating expression and because it's superfun to kill off the villain with it just to rub salt in the wounds.
Similarly I love Platform Bot for Blade's WTF? expression.
Turret mode is a great card when it comes to theme and flavor. Still one of the only cards that made me actually laugh out loud when I saw it. BUDABUDABUDABUDA!!!!
I also love the various cards that show the progression of Ambuscade sneaking up on Haka while he is holding some balloons. Haka's final expression is priceless.
Grace Under Fire, for the flavor text ("When life gives you lemons, make a lemon cannon!") or a card in Setback's deck just for its excellent blending of flavor and gameplay mechanics.
there are sooooo many. I can pretty much say any card for one reason or another. But my absolute favorites are these 5
Three from the Past
1. Into the Stratosphere,
2. End of Days.
Why from the past you say? Because of all the shenanigans you used to be able to pull with these cards before >G put the kaibosh on them. Drug cards? Huginn/Muninn, Operative? .... Man... good times.
3. Savage Mana. The original printing.
"GET IN THE HIPPO SUIT. "
"but please mr. haka, I don't wanna..."
"NOW!!!!"
and two for the present;
4. Elemental Wrath Absolute Zero
5. Darkwatch Mr. Fixer.
Because these two cards took hero decks that I wasn't really interested in playing and instantly made me interested again.
Freedom Tempest's character card - I don't even care to play as him that often, but that is some of the coolest art ever; him standing on the rocks, pissed off, waves crashing all around him, summoning an arm of pure lightning in place of his missing one.
Nightmist's Oblivion - because it looks about as wickedly strong as it is.
Legacy's Flying Smash - Legacy seems like a guy who is gifted with all this power, and yet doesn't wish to unleash his full potential; he'd rather be there for his team and do what's right, never letting things get too violent. Flying Smash seems like a little taste of Legacy letting loose; flying straight through a giant floating structure and causing it to explode from sheer force.
Haka's Punish the Weak - I rarely use the card, but I love the art and Haka's pure, uncaring expression as he squishes heads like grapes.
I've never seen the original edition of the game; could someone link me to the art and pre-revision mechanics that I'm missing? I know such a link exists, it was placed for me once before but I made the mistake of not swallowing it whole so it could be with me for always.
As for my favorite cards, here's an off-the-cuff top 5:
1. Final Dive. Perfect marriage of flavor and mechanics; one of the few things I really like about playing Fanatic.
2. Brainstorm. The flavor text could have come out of my own mouth.
3. Pillars of Hercules. Way to turn the game up to 11! Time Flies is a close second.
4. Young Legacy. Turns my single least-favorite hero deck on its head and makes it cool again. Plus she's cute.
5. Power of the Ennead. This is me cheating and naming an entire Villain deck, rather than try to decide which card in that or some other Villain deck is my favorite Villain card. The Ennead are just about the coolest anything ever IMO. Atum is my favorite, because of those little fire-beetle things of his, but you have to have the entire deck to really see how he and his followers work together.
I'm afraid I have to disagree with Into the Stratosphere being perfectly flavored though. If you pick up Citizen Spring and throw her that far away, she's NOT going to come back at full health the next turn; it's even sillier with a Lost Child. And how exactly do you pick up and throw Superhuman Redirection, Luminous Leadership, or an Apocalypse?
What cards are these? Are they in the original edition or have I just not noticed them? I remember PCD and Haka of Shielding showing Amby surprising Haka in mid-sandwich, but I don't remember balloons, and anyway two cards is hardly a "progression".
The card where Haka is pulverizing Hippo-Guy (first-printing Savage Mana?)
The Tachyon divider card where she's chowing down (did that appear anywhere else?) It's on her bio page, but you have to click the banner to get the full effect.
My favorite, although there was not graphics at the time, is the original T.Rex from Primalis. He used to be able to hit himself. The first time we had one played a guy in my group basically explained the senario (since the T.Rex was going to hit himself) as such:
A T.Rex moves quietly through the jungle. It looks around and sees something moving in the bushes. Lunge. Chomp! *Yelp!!! That's my tail!!! *Wimper