Quoted from spidey:

The key to ST is to play it "correctly." That means, don't play Level 1 modes one after another. It's always best to dig 3 down on whichever level you start with. This will lock in a shot multiplier for the rest of the game, and it keeps the modes from feeling too similar, as L2/L3 modes are usually better. I like Nero 1/2/3 the best, but also go with Klingon Battle about as much. Those give you the two best shot multipliers and are also generally the most fun trio of modes. After that I like to just mix it up. DtD 1 is fun with the left orbit shot multiplier locked in, and you can start Away Team (galactic spinner). Top that with double scoring and your head explodes with fun. You can actually combo the left orbit over and over with slap shots if you do it right. And don't forget to bring in the Vengeance modes every now and then (I tend to forget, myself) because you need EB on V2, and multiball on V1 can help finish modes.
Can't hep with X-Men...