My highest was on my V2, I got 34 generations from it. The highest I've had on my ID L though is 13 then it dies, it's sad because I have to start again then!
Generation 18. until I forgot to pause it when I went to school and I texted my mom to take care of it and she killed it right now I'm on Gen 8 on my Tama-Go
When I was little (like 10-11) I didn't even know the v3 could have multiple generations!! I Think the oldest it ever got to was maybe 7-8 days and then it would die on me! I'm working on it now though! I got a new one.
I think I got to around 37 generations (continuous play) on my V1 Connexion before it got tabbed up and given a rest.
Other tamagotchis usually around 18 - 20 generations before they get tabbed up.
(All my generations counts are based on continuous play, I don't continue the count on a generation if for some reason my tama dies - when that happens I go back to G1 and start counting up all over again).
Maybe around 3 or 4 before I get bored. I recently bought both an ID L and a P's. I'm on gen 2 with the IDL and I wanna play the P's, but I don't want to feel like I'm abandoning the IDL. I'll try to wait about a month before I move to the P's, then switch back and forth.