All good choices so far. One comment I'd like to make regarding the speed of an EM or SS. A properly restored or reconditioned game will play fast (for it's time period). A poorly done game will plod along - no flipper kits, sluggish drop target and pop bumpers, filthy mylar etc etc. Give me a slow EM and I'll make it play fast. Same with SS. Jady's suggestion of Skateball is 100% - That game is "as fast" as any DMD. Nick's Firepower is as fast as any DMD (New playfield). You need a point of reference with regard to the speed of the older games. A fully restored EM and SS will play at it's full potential when reconditioned or restored properly.
EM - Spirit of 76, Buccaneer, King Pin, Sky Jump, Target Alpha and Surf Champ
SS - Black Hole (widebody), Firepower, Skateball, KISS, Fathom, Joker Poker, Galaxy and Meteor
The "ultimate" combination would be Medusa / Meteor and Target Alpha / Sky Jump