It depends on what you like to ride. if you want to ride dj's/street/park go for a hardtail bike, roughly a small frame, cause your 5'5" and it would fit you better, and you would be able to jump around more...as to the type of bike, im not too sure...that comes down to your price range, and what compenents your looking for...if you want to go big, do drops, and big jumps, biasically freeride or downhill...then i would say go for a dual suspension bike that has a dualcrown fork, or a 6+ inch single crown freeride fork...but...again it comes down to price range, because for a bike like that, it can range from 2grand upwords depending on what company you buy from...for dj and park, some good hardtials that i've riden, and love would be the kona cown, specialized p series, and norco has a line for dj/park specifically, as does haro, k2, garyfisher, and a bunch of other companies...if you want a freeride/downhill bike, then i would recomend maybe the kona stinky or coiler, i've riden them both, and they are a well built bike, and will easily take upto 10foot drops, and alot of abuse. another freeride bike that i've taken alook at, and have played around with is the specialized bighit, they can be as pricey as the kona stinky and coiler, but, they have a more flexible range thats around $1,500 and up vs $2,000-$3,000. but again it really comes down to how much your willing to spend and your riding style, and what you want to ride. but if you have any questions, i'de be more then happy to answer them, just hit me up :). Good Luck on buying your new bike, i hope i was able to help you out :)
