the first tama (gen 1)
in 1997 bandai made the TAMAGOTCHI a small egg shaped gadget that had 3 buttons and a small black and white screen. this is what started the craze they were HUGELY successful! lots of people had them. this tama is not my favorite but I still like it. if you have ever taken care of any tama you can understand it.
angel
the tamagotchi angel was made after the gen 2 and was made to help kids who were sad about there dead tamagotchi. 4 colors were made a pink a blue a wight/pearl and a only American green/yellow. all were pearl. this one was intended for lazier care takers as this is the easiest tamagotchi to care for. 2 versions were made 1 with p1 icons and one with angelgotchi icons like the duck on the japanese one is now a butt with wings. this tama also has motion sensors wen feeding it candy you must tap it to chase the bat away. this is my favorite old tama!
Osutchi
bandai's 4th tama was the tamagotchi mating or osutchi mesutchi. they'r new feature was that they would mate when they were at there last stage they would connect through the top and do a little animation and then you would have a baby on both tamas! the pic is of the boy tama (osutchi) I also have the girl but my friend is in control of her. I found this at a great price!!!! only 17$ free shipping!!