I've always reaaaaaly like the Tamagotchi Ocean myself. Yeah it's a lot harder to raise but the characters are really neat and cute and it's an hand held aquarium kinda you know?
But if you want somthing easy to care for you can't go wrong with an Angelgotchi. They aren't very demanding at all, and they are even cuter than the orrigional Tama's ( I think so anyway) and it's got the really neat twin angel secret character. That's the first secret character I ever had and I had no idea about it when I had it. So you can imagion how happy it made me.
Of course, V1's are good. Just make sure to get one that isn't of the first wave colors as those are defective. I've never played with a V2 and the V3's are really really nice. Or just wait and get a V4.
I'll even mention somthing that's not strictly a Tama. Get yourself an old school Digimon if you want to try somthing different.