Really depends on what they want to be closest to....
Next to Spinnaker & Club LaVela, The Summit is a popular spring break place...although, probably also the wildest. I would rent that one from VRBO so you can look at unit pics. The rental office is not recommended as many of the units they represent are very outdated and you can't specify what you are getting. On the other side of those clubs, Boardwalk Beach Resort is a hotel option. Sunbird is also a close condo that has all 1BR units.
Closer to Pier Park (although still a good hike to it), Seahaven is an option. It's an older hotel, but is beach front. "Origin" by Seahaven is a newer condo with 1BR units that is across the street from the beach, but is part of the same Seahaven complex. Easily walkable to Pier Park, The Osprey is a pretty good place hotel-wise. Beachbreak is also relatively close.
Holiday Inn is very nice and they'll be walkable to an arcade, some restaurants and a bar or two...but they'll have to drive in either direction for Pier Park or Spinnaker/LaVela.
Sandpiper Beacon is also a popular place, but is sort of a destination unto itself. It has alot of amenities of larger places, but isn't really close to anything...they'll need to drive almost anywhere they want to go.