Well, toysrus, target, and any place that sells them are usually out all the time, they are INCREDIBLE popular and its hard to even get your hands on one, so get whatever you can get. Battle and Starter packs are rarely ever seen, the best bet you have would to find a couple of booster packs in the big hole in the action figures section where the bakguan should be(they are so popular its not even a joke). So good luck, and just get whichever one seems to fit you best, or that you like the best. the cards are random, but I which element do you like(aquos(water), pyrus(fire), haos(light), darkus(dark), ventus(wind), subterra(land)?) Either go for them all, like me, or pick a special attribute that you like the most.
Oh this may help you decide, it is a list of all the bakugan that are available for purchase(note every bakugan comes in more than one attribute and the same bakugan with a different attribute will have different power levels and abilities). Heres the list:
http://i38.photobucket.com/albums/e137/SaM...omoPoster_B.pngMy bakugan info:
bakugan type preference: anything I can get my hands on, I love pyrus, haos, and aquos types, subterrar are ok, and there are only a select view ventus and darkus bakugan I like.
My bakugan (from left to right for the pictures) :
traslucent aquos laserman(450gs), pyrus tigrerra(400gs), darkus juggernoid(350gs), pyrus dragonoid(350gs), subterra robotailion(300gs), aquos pryus(250gs)
http://i38.photobucket.com/albums/e137/SaM...ugan6closed.jpghttp://i38.photobucket.com/albums/e137/SaM...akugan6open.jpgcards (from left to right for the pictures) :
Reaper, Reaper, Saurus, Serpenoid, Serpenoid, Juggernoid
http://i38.photobucket.com/albums/e137/SaM...kugan6cards.jpgPS: Each person who owns bakugan chooses a guardian bakugan, wether it be your first, most powerful, or coolest looking, you pick one. My guardian is my aquos laserman, since he was my first, is my most powerful(at450Gs), and he is translucent(translucency only means that the bakugan is more rare than others and it looks cooler).
Here is a picture of my guardian bakugan, Aquos Laserman, up close:
http://i38.photobucket.com/albums/e137/SaM...kuganmarble.jpghttp://i38.photobucket.com/albums/e137/SaM...bakuganopen.jpg