Quoted from TheLaw:

Add a poll
For me it's Met easy but I'm not a fan of ACDC. I think Met is set up almost perfectly as you progress through the game.
The Crank it ups, the doubling score before you leave, the inline drops etc....everything just seems pretty perfect.
Metallica music sounds like 2 ugly teenagers FB'ing each other in plastic bag filled with starting fluid, whatever the hell that means, and it's still an all time great.

Quoted from per3per3:

Having previously owned a Met Pro and currently own an AC/DC Premium, I'm happy to weigh in.
AC/DC Pro vs. Premium: There is a dramatic difference between the pro and premium models of AC/DC...and it's more than just the lower playfield and cross-over ramp. The stand-up targets on the pro vs. the drop target banks on the premium have a significant impact on the way the machine plays and I much prefer the drop targets because the ball doesn't fly around so wildly (i.e. the ball travel is more predictable off of the drop targets). Also, the color changing LEDs on the premium make the deep rule set easier to understand by providing visual indicators for what to shoot for. This shouldn't be overlooked as the code is deep and the ruleset is not always the easiest to understand at times (i.e. what to shoot for at any given time). The swinging bell is also awesome on the premium and is a very cool, satisfying shot.
Met Pro vs. Premium: There is definitely less of a difference between the two versions. The met premium has the rising cross (static on the pro), the motorized snake jaw (static on the pro), the hammer lock (static newton ball lock on the pro), and two spinners. Other than the hammer lock which is awesome but some folks complain it blocks the view of sparky and is less flowly than the pro's lock and the spinners, everything else is aesthetic. Also, same as above, you shouldn't overlook the color changing LEDs on the premium as they are very helpful and also look better. Having owned the Met Pro which didn't have them and now the AC/DC premium which does, I highly prefer the color changing LEDs and they are especially helpful as you learn the game and help non hardcore players enjoy the game more.
Conclusion: As others have said, I don't think you can go wrong: both are really fun, fully featured games with deep code. If you like flow and more of a challenge, I'd recommend an AC/DC Premium. If you're more into mode-based gameplay and love yourself a good bash toy, then Met is probably better for you. They are both great games and are probably the two best games that Stern has ever produced. Come on over and put some more time on the AC/DC and I know someone with a Met Premium that you can get some quality time on as well.

Quoted from AJB4:

You CANNOT go wrong with either. Most would give Met the slight edge over ACDC - but personal music taste also comes into play. Interestingly enough, both games are awesome in the Pro version so you don't have to lay out that extra cash. I would also recommend that you look at Aerosmith Pro or Premium... Again the AS Pro plays great, but the Premium has a few more features if you think they are worth the $$$.