Liking Tamagotchi does not neccessarily mean you'll like Neopets.I say this from experience.I love tamagotchis and Loathe Neopets ( except for the micropet-like voice activated neopets.Those are awesome.Love my Kougra. )
Neopets are an entirely different animal than Tamagotchi.They are not animated as tamagotchis are,they do not change and they do not die so there is no real incentive to care for them.
Basically what a Neopet is is a picture of some strange creature.That's pretty much all it is.You cannot interact with it as you can with tamagotchis.tamagotchis actually respond to you.Neopets don't.You just get different pictures of the creature if it is happy,hungry,sad etc.
Some people love the site,so I figure they must be doing something right.It's got some fun games,but since I can get much better games on my Xbox,it doesn't hold my interest for long.As a virtual pet at least for me it's a non entity.It doesn't do anything or really react to you or anything.I'd take even the worst Tama knockoff over any Neopets internet pet.
But of course this is just my opinion.You may very well love the site and if you do,more power to you.My account has been sitting there unused for years.