It depends on what kind of Tamagotchi you like and how much time you have on your hands. I don't have a Music Star, but from what I've heard it's quite a good one. I think you should read a few Music Star logs to find out more about it and if it sounds good to you, then get that one when it comes out. However I've also heard that the Music Star's more needy than any previous Tamagotchi.
If you like to be kept busy, go for a v4/v4.5 if you can find any around. I'm not a fan of these two, but other people like them because it's jam-packed with games (some are quite long, in my opinion) and you have to raise your Tamagotchi to get a job and be successful in life, then find a mate for your Tamagotchi and do the same for the next generation.
If you don't have much time on your hands at all, just go for a v5/v5.5. They're very easy to keep satisfied. Every hour all you have to do is either give a meal to keep it full, or feed a snack or use an item to keep it happy (you can also play games but it's not necessary because you don't have to keep your Tamagotchi's weight down on this one). Whenever you do have time on your hands, you can try and raise its bonding percentage to get different characters. I find that it's best to run this one alongside another Tamagotchi, though that's just me.
And if you like the more simplistic Tamagotchi, I'd say go for the v1, though most others would probably disagree with me and say v2 or possibly even v3. The main aim of v1-v3 was just to care for a Tamagotchi, keep it well fed, content, fit and well behaved and later on find a mate for it (either by matchmaker or connecting) and look after your Tamagotchi's children. v1 was basic and didn't have very many characters compared to recent releases, yet I went through 104 generations and never got Hanatchi. v2 just added Gotchi Points, the ability to buy items from the shop (as opposed to getting them randomly while connecting on the v1). Finally v3 added a very basic Tamatown connection (and a little antenna which really annoys me
).
So yeah my opinions... I hope I helped and wasn't too confusing!
