If I could only have 1 pinball backglass to hang and display would probably say Baracorra.

Honorable mentions are:

Strikes and Spares
Fathom
Embryon
Silverball Mania
Woah Nellie
Pinball Pool..Joker Poker...Genie...Jumping Jack (I just love those Gottlieb girls)

There was also a game I saw at the PAPA headquarters that I remember really liking the backglass on. I believe it was an early solid state and had an area in the upper left part of the playfield that you would get to as soon as you plunged the ball. It had 1 or 2 flippers up there and almost felt like it's own playfield. If you kept the ball up there long enough the flipper (or flippers) would eventually die and the ball would then come on down to the rest of the playfield. I don't even remember much about the backglass except it had some nice looking ladies on it. If anyone could give me some help on this one it would be appreciated.