Quoted from pinsRfun

Buy something other than Tommy or DM.  If you're a fan of The Who, get their tunes.  No point wasting big money on a crappy pinball just cuz DE slapped some graphic on some wood and passed it off as a pinball machine.

show tunes - not the WHO

If you are buying for investment purposes, Tommy will be worth a few hundred more next year probably. If you are buying to play and have fun, DM is a better playing game.

Tommy uses soundtracks from the play, not the actual Who tracks, which killed the appeal for me. Play quality is so-so.

However rock themed games are always more collectable in the long run.

Tommy average value on Ebay $1659-1891
DM "         "        "         "       ~$1154 US

Highly variable depending on condition. Tommy will increase in value.

Agreed with Mr Hyde, get both.

If I had the space to put more pins in my basement, I'd definitely own a DM.  It's a fast paced game, that has the right number of playfield gadgets for me.  I absolutely love the handle mounted buttons.  It makes it a very physical game experience for me.

I plan to own one someday.  

Tommy has no appeal for me.  I agree that the synthesized soundtrack gets on the nerves after awhile.  It would have been far better with a real vocal soundtrack.  Decent gameplay, but like others, I can't get past the music.

tommy could go up in value after there superbowl performance this year.
buy a congo