Each dorm definitely has its own personality! That said, don't worry about being stuck in the dorm of hell- the Dean of Housing is certainly aware of this, and takes it into account when you fill out the housing form each year.
Parrish Hall, the central building on campus, not only houses the administrative offices of the college, but also students on it's upper floors. These halls are separated by gender, and tend to contain the more substance-free students on campus.
The newer Dorms, Alice Paul (built in '04) and David Kemp (built '09) Halls, definitely have the advantage of the most modern bathroom and lounge amenities! These dorms are located at the foot of campus. While there is a good deal of hall bonding in these dorms no matter the student, AP tends to house many a student athlete and mellow student, while DK holds kind, ambitious, and studious students.
Just north of AP and DK halls is Mertz Hall, an incredibly homey-feeling hall with a close hall life. Architecturally, it has wide stairwell landings with larger rooms for freshman doubles.
On the east side of Parrish lies Willets hall, home of the partying underclassmen. As this dorm is the most densely populated and lively of the halls, it is generally considered the most undesirable dorm for students who don't wish to be in close quarters with their comrades. Yet, it houses the greatest amount of first-years of any dorm, and provides a great opportunity for underclassmen to bond with their fellow classmates.
Next to Willets are the Lodges and Worth, home to upperclassmen. The Lodges are about as cozy as residences can get, with 1 first-floor triple and 1 second-floor double per cottage.
On the west side of Parrish is Wharton, the other primarily-underclassmen dorm. Wharton has a lovely courtyard overlooking the outdoor tennis courts, and is divided into three sections. Wharton residents are incredibly laid-back and often enjoy using their courtyard for many a pre-party!
Near Wharton lie Twin Dorms Dana and Hallowell (aka Danawell), conjoined by a trailer. They hold a fair-but-not-substantial amount of first-years, but bonding still exists within the hall: the trailer provides a space for residents get together.
Lastly, the most dreaded of all halls, is Mary Lyon. Located 20 minutes walking distance from campus, this dorm definitely loses appeal on the commuting front. However, it's remote location makes this dorm incredibly intimate with a the most lively hall life of all the dorms. Usually, the reputation of Mary Lyon students is the opposite of the Willets student: more typically "nerdy" and insular. Yet, recently, you can tell that the housing committee had really tried to add a diverse group of students in there to negate the stereotype.
Apart from these, upperclassmen mostly live on partially-off-campus-houses 5 minutes away from campus with friends, such as PPR, Kyle, Woolman, and Strath Haven Apartment Complex. Here, housing really takes on a homey meaning as students make closer friendships and transition into the real world.
As you can see, there's a place for everyone, and the options get better with time.