I'm currently on 7th Generation on my TMGC+C, and it's Kuribotchi. I'm sneaking them into school and raising one generation per week and not hanging around when they become adults; instead I use a cheat to get the Dating Place then marry immediately. I've had a mix of girls and boys, 5 girls and only 2 boys.
I got up to 78G on my V1 but then it got dunked in water so I lost everything. >_> The tama works okay now but I've lost all 78 generations... I've started again and it's on gen 8 now.
I'm only on my 3rd Gen on my v4.5. I plan to run my v4.5 until the battery dies. I don't ever put my v-pets on pause on purpose (a couple of times I've found that my pocket will pause them) so I'm always playing with them.
Once I get a new battery for my v5 I'll be playing that until the battery dies.
I've found that the tamagotchi's are easier to raise then the other v-pets I've been raising, so I never get tired of the tams. This Fairy Magic pet is driving me crazy!