Add that to the fact that he was quite a beast when all we had to play with was Infinity Challenge... and he was a pain in the neck to get a hold of, back then, as well.

His weakness is his damage, which peaks after a few clicks at 4, but only for a click, with lots of clicks of 3. For his price, you could build a team of figs that could be as effective, and get more action economy. For example, for about the same price, you could get vet. Bullseye and vet. She-Hulk, and be more effective because you would have two attacks instead of one.

I know everyone doesnt play this way, but if you dont mix universes and dont allow dupes, he is a beast. I believe only Black Panther and Mandarin START with Outwit. DC is much different, but in a 10 round Marvel only tourney, you are probably not going to lose Thanos.

There is also the issue of makng a character the way he is rather than number crunching to see how much death you can churn out for the least pts. I was never much of a table top gamer before this. I got in because I love superheroes. I try to play conceptions and teams and make it work. I lose a lot, but I feel better about it. Of course evreryone likes to win, but I hate Cheese.

Cheese example: Bane!
Not talking about Marvel or DC, just the way they made Bane.

I'll always back Thanos as a viable fig.
While he is tough to make effective in a 300 point game, in a 400 pointer he can be really effective. He's Enhance/Perplex/Shield friendly, and you won't have to waste Perplexes on his AV.
Another thing that everyone seems to overlook is his two lightning bolts. While Perplex doesn't help this, shield and Enhance do considerably.
He has 11 clix of life. Even with an Outwitted Invulnerability, he should have some longevity. If you don't stick him right out there to get whomped on, that is. If the opponent's team only has one Outwit, you will be hard pressed to smash through his Toughness for a KO, and if you do, there's always that off chance that he will land on Regenerate.
The problem with Thanos, as others have pointed out is his lack of powers. He's very "vanilla", especially when compared to other figs in his point range. He needs his own taxi to get into attack range, whereas Thor/Iron Man/Annihilus/Dr. Doom/Blastaar/Crimson Dynamo LE have running shot to get themselves into position.
Personally, I don't necessarily like having it that easy. To be honest, I haven't even played Thor yet. I like a bit of a challenge, because if you can get a more challenging piece to accomplish a strategy, the outcome is that much more rewarding.
I still like Thanos a lot. Then again, I have this nostalgia thing for a lot of the figs in IC.

BTW - I once played in a 3-way one fig each battle of Thanos VS. Thor VS. Kang. (I fielded Kang - for some reason, I thought his double lightning bolt/Incapacitate combo might keep the other two at bay. Boy, was I wrong.) Anyway, Thanos ended up winning it, believe it or not.

Thanos is an amazing piece in a 400 point or higher battle. When he is used with other pieces he can completely dominate a game. I like to use him as the big bully who takes on the smaller guys, and while my other figures weaken or tie up the opponents bigger pieces. Thanos can walk up to almost any figure under 100 points and take them out, even the best small pointed figures need sevens to hit him and then only U elektra or Wolverine in the first set can do the high damage. Bullseye could only do 2 damage and the smack back would effectively end him. Of course Firelord is the piece that could do some damage, but you can take him out if you get the first shot, cause Thanos almost never misses. I feel that Thanos may have lost a little when being compared to the newer figures like Dr. Doom (who is the new dominator in the universe), but he is still a very good weapon that can win a game or at least take half the other team with him when he goes. Yeah he could use a few more bells and whistles (Thanos, not Doom), but he is a very good representation of the mad titan, and I think he is worth keeping in the rotation of higher figures. Maybe # 3 or four of Marvel figures over 150pts. (Dr.Doom, Thor, Ultron, somewhere in there) Just my opinion.

Thanos is a monster!! His AV throughout his entire dial is awesome and he takes damage extremely well so you can move him in, let him absorb damage then return fire for big damage. He could use a couple more clicks of 4 damage, but I think the real problem is cost. In my opinion building a 300pt with a guy that is almost 2/3 of the build total is crazy. Thanos only does 4 damage max and mainly does 3. I just have to tie him up with someone with inv until his support is dead. I've built a team that used E Sandman to tie up the main attacker while E Firelord and U Nightcrawler take out any support characters. I just have to place a medic behind Sandman to keep him healthy and maybe R Destiny to prevent you from breaking away.

Let's say you taxi thanos around with R Vulture, that gives you 100pts to work with and you arn't going to find a lot of help for that. IE V Bullseye + R Vulture = 58, plus maybe a cheap perplexer or 2 and a paramedic. All of which won't be any match against my team with your big gun out of the way.

However if you bulk up your perplex you will just have to look out for outwitters. You could take a couple taxies (in case you lose one), a barrier char or 2 to block LOS of the outwitters and a couple perplexers and you might have yourself a killer team.