This is really a personal decision, there is no right answer. Play both and decide.

I like both games myself for different reasons so since you want opinions, here goes:

ACDC is fun, fast and in your face. The song choices are good and I like ACDC music. The lightshow is awesome but the canons obstruct the lanes (no way around that). Deep rules but easy to grasp after a bunch of plays. Not your typical mode based game.

Aerosmith is fun, colorful, they picked a nice selection of older Aerosmith music (for the most part). The jack in the box toy is fun, game is fast and has an interesting smooth layout. Fun rules, not that deep but deep enough.

Personally I like the SAM system better than spike, though the color screens are really nice on the spike games. Aerosmith animations are fun for the most part but it took several plays to get used to the 'style'. I really like the ACDC colordmd so I'd put them about equal.