If I'm reading this correctly, according to this thread: https://pinside.com/pinball/forum/topic/pinsiders-christmas-quiz-on-pinball-history#post-112973 it looks like Black Knight 2000 was the first to acknowledge a successful combo shot?

And to answer the original question:

I see someone linked ST:TNG - good choice; I assume this is for the Picard maneuver, I agree that it's really satisfying to hit. Really, I am just a fan of games with good flow, so whether or not they're true "combos," I like being able to hit consecutive shots on the fly. White Water has a lot of fun ones, even just hitting multiple hazards in a row, or something simple but important like Spine Chiller to Insanity Falls. Johnny Mnemonic has combos for days; not really any specific named ones, but hearing "AGAIN!" when you're nailing a bunch of shots in a row is always fun.

Of course, End of the Line is really satisfying to hit too.