I just got back from 3 weeks in this area.
If you are looking for a resort type feel - Clearwater Beach Marriott Suites on Sand Key or the Vinoy in downtown St. Pete. Both are nice with many differences. The Suites like sair earlier isn't on the beach but they provide a quick shuttle service. Really nice pool area and your a quick trip from the touristy Clearwater Beach area. Only negative I had was the rooms are a little dated.
Vinoy was nice. Very historic hotel and had great restaurants. Nice pool, fitness center, golf course and spa. Negative here is no beach and the some of the area nearby isn't the greatest. Right y the hotel is nice but 5 blocks inland after that isn't great.
If you are looking for on the beach - The Residence Inn Treasure Island is very good. I was impressed. Updated rooms which ae very large. Had a luxury type feel which isn't usually the case for the Residence Inn properties. Only negative was the pool which was pretty generic and nothing special - but the hotel is on the beach so not a big deal, unless you are a pool person.