"teddy bears" are actually syrian hamsters...
PLEASE do your reserch before purchasing one as petstores always sell them to whoever can buy them...
for example Syrians are SOLITARY and most will, once they hit sexual maturity kill their cage mates... (so flnatv be prepared to seperate them) syrians are highly territorial and in the wild would ONLY come around other syrians to breed. while SOME folks can keep them together without problems, most syrians are incredibly nasty towards other hamsters and will fight, often to the death!
teddy bears are the "long haired" version of the syrian, but theres aldo the black bear, golden ect, they are all just different coloration of the wild type syrian.
"Syrian hamsters are solitary animals and should not be kept together when housing, the result would likely be aggression and conflicts that could result in serious injuries and possibly even the death of one of the hamsters."
http://www.hamsterific.com/SyrianHamsters.cfm
dwarf hamsters however are relitivly social...
the russian dwarf (campbells) are adorable,
winter whites remind me of the russians but are better known as siberian dwarf hamsters, very similar in looks but usually lighter coat colors
and the chinese, they remind me more of a short tailed mouse though, they have a slightly longer face, i think their cute.
but i have to say of all the hammies my favorite is the tiny tiny Roborovski (aka robo hamsters) their tiny, their cute and their funny lol
but in terms fo lots of "breeds" thats it, there arnt lots of breeds, theres the syrian...which comes in lots of verieties, they are not seperate breeds, just different hair type and color, (like having a long haired dachshund vs a shorthaired dachsuhnd, a red dachsund vs a black and tan dachsund, there all dachshunds though.
then theres the 4 dwarf breeds.
dwarf breeds are the only hamsters that can safely be kept in social groups.
i will add, while i do think mahsters are cute, i thing rats and often mice, make much nicer PETS, being that they are social animals who bond well with humans...
syrian hamsters being solitary animals dont crave companionship so arnt as social as companions..