TZ

Road Show as well

Depends on your budget. Also you shouldn't judge a game on number of targets. On paper I know that always seems like it is a good thing, but it really really depends on the game rules as to how well it all comes together.
Some games have targets that are mostly useless or are only useful during certain modes or whatever. Which isn't always a bad thing. But there are games out there that might have fewer things to shoot at, but you can gun for them all the time & really let the ball fly without too much thinking.

Basically what I'm saying is that deep rules & very difficult final goals aren't always a good thing. It can make things frustrating as well.
Personally I'm all about having a good mix. If you can only own 1 game then I suppose go with something that might have deeper rules. If you can own 2 or more games I think its also good to have a game that requires more reflexes & less thinking.
Also, sometimes just a well written but streamlined bit of game code & rules can be every bit as good as a sloppy mess of modes.

I swear some of the more addictive "just 1 more game" games are often have a more basic rule set. I think its good to try to appreciate both types of games.
After all these years I'm still not sure which I prefer. A game is either good or it isn't. I've been hooked on simplified games, I've been sucked into deep games as well.

Road show

If you are looking for a game on the cheaper end of the spectrum.

Challenging with short ball times and nearly impossible to 'finish' for most people = Fish Tales

Challenging with longer ball times, great shot variety, and nearly impossible to 'finish' = StarGate

Both games are completely different in style of play and feel, but both are awesome in ANY collection!

From my collection,

Batman Forever has interesting shots. Some of them very tight, and all of them really fun.

TZ 9.4H

RBION or TZ
Something with lots of shots, variation and different modes and lots of depth

congo, and LOTR!

I'd add Judge Dredd to the list along with Twilight Zone and Road Show.

JD & RS - many shots on both and both wide bodies too. I'll add Flintstones for the boulder crushing (copied in POTC) and the looping inlane returns are my favorite. Finally, Blackwater has a nice left side return and reverse flipper.

Ben Hecks game Ghost Squad has some Cool unique shots .

LOTR and TSPP

The bridge shot on Escape From the Lost World is interesting .