I own both, and I hope they stay in my collection forever. I've had some epic games on both machines. They are a tie. Even in the top-100 they are both about 100th place. Tiebreaker goes to Sorcerer only because it's slightly more interesting.

I use these six groups of criteria when choosing a pin: (I'll include my vote)

1) sound: Tie
2) artwork/lighting: Sorcerer
3) scarcity/likelihood someone won't let it leave the collection: Sorcerer
4) replayability+flow+fun+multiball fun: Tie
5) popularity/resellability: Space Shuttle
6) unique features: Tie

I'd say scarcity is the tie-breaker here. It's much harder to find a Sorcerer. If you find one, grab it. That would lead my decision. Odds are better than you can wait and find the "right" Space Shuttle you are looking for.
-mof

This exact poll/question has been asked on this site twice before.

Good insight mof! I like your categorizations. You sure Space Shuttle doesn't get the point for unique features?

Sorcerer:
Opposite-side flipper with drop targets
Hateful playfield lane-change switch
Backfield eyes

Space shuttle:
Outlane diverter
Side-swipe drop targets
Drop target protected ramp
Randomized reward
Spells TILT when tilted

I love Sorcerer, and it's got my vote, but I have to admit that Williams went all-out on features when they made Space Shuttle.

I think they are both incredibly well-balanced games. I play them for the balance, and long fair games, not for the "toys/gimmicks"...

Glad you like the categories.
-mof

Space Shuttle!

Plus, it's got a rich history as the pin that saved Williams from bankruptcy. What else can you ask for?? BigB

I own both, and I love both. They will never leave the collection. If I was forced to keep just one it would have to be Sorcerer. This is the game that got me hooked on pinball when I was young. The pizza place by my school had one and i could often make my quarter last a whole afternoon. I really love the sounds and shots in this game.