Avengers, but......
The Avengers has to be modded and dialed in. Here's some things to consider.
1) Stock setting on Avengers is horrible. For instance, you want to Finish Black Widow, GOOD LUCK. You have to shoot her shot 3x to "Start". You have to shoot it again like 10x to "Finish" and then you go into Black Widow Vs. Hulk, which is fun, but then you have to shoot Black Widow at LEAST 2 more times (and Hulk too of course). So. I'm not good at math, but that means you have to hit the widow ramp PERFECTLY about 15 times to Start/Collect/Assemble/Finish her mode. Read this as IMPOSSIBLE. Other shots are still chopping wood. SOLUTION: Turn the modes to Easy, even Extra Easy, and this game OPENS up. You start activating the VS. multiball modes, which are a real treat in the game and really should be something you can achieve every time up...
2) Loki blocks your view to Nick Fury, which is kind of a big deal, since he is the Add-a-ball for all the multiball modes. So, you HAVE to move him.
3) LOKI lights are impossible to see. Mod required to see. Mod is nontrivial. BLergh.
4) Tesseract cube is garbage, upgrade it and it becomes Awesometown. Like seriously, one of the best mods you can do for a game.
5) Full Plunge almost always causes a bounce back to loki, which sucks. So you need to work on that plunger and the launch ramp stuff to dial it in so a full plunge goes into the pops (really nice for completing Cap'n during multiball.
6) BLAH BLAH BLAH. You can read about it in other threads, there are other things you have to do too.
But... BUT.... If you do all those things, Avengers is a superior game to TF. No doubt. IMO, of course.
-Wes