Really a great pair of pins. I've owned both. Sold both. Have repurchased a taxi, and am somewhat looking for another pinbot.
Taxi is pretty easy to "beat", i.e. pick up all passengers. The bells is a cool feature, and the call outs are super unique. The layout is great too. Just a FUN pin that people love to play.
Pinbot is a much more difficult pin in my opinion. Beating the game, i.e. reach the Sun is damn near impossible, at least for me. The sounds and music on pinbot are some of the BEST in pinball.... actually theyre amazing.
VERY tough call here. Honestly, slight edge towards taxi, but pinbot is right there.
Side note: there seems to be a lot of pinbots for sale on here. Most 2k+. I think that's a crazy amount for a pin that was mass produced.