well... if your budget was larger i would definitely recommend the audiotechnica ath-m50s. they can be found on ebay for $100 sometimes. often as "open box" but still brand new. (returned within hours of buying since they wanted the m50 which is the coiled cable version).
however for $50 i would have to say you might want to give the ath-m30 a try. while not as great as the m50s (its 1/3 the price) and while it doesnt have the bass of the m50s (but again its not lacking either) its a pretty balanced headphone.
here is a mini review by an actual user.
http/www.head-fi.org/t/119043/mini-review-audio-technica-ath-m30
i'm not saying they are they only headphones to buy... as there are plenty other good choices but it may be worth checking out. since you dont like excessive bass like the XB and seem to like the style of large over the ear studio type headphones i recommended the m30 as a possible suggestion. your choice. read reviews, check what other people out there are saying.
the ath-m30 can be had on sale for $50 at guitar center sometimes or perhaps even less on ebay.
you can find quite a few other suggestions by looking in google for "best headphone under 50"