Just got back from a week in Colombo and decided to spend some time looking at options beyond the Hilton.
Park Street Hotel is a great find!! It's in a quiet little 'hood wedged between the two lakes, a few blocks from the Hilton Residence (not the Hilton in the Fort area). It is stunning, very modern and the website doesn't lie. I have a ton of pics if you want PM me and I will send some. More information at
http://www.taruvillas.com/parkhotel.html. We also stayed at Taprobana, an hour + south on the beach and it was nice, but not quite as nice as Park Street. Park Street is my new home in Colombo. We had a staff of 5-7 pretty much dedicated to us. It has a nice compact pool, and the rooms in the converted warehouse are striking with 15 foot ceilings.
We also checked out this place, Casa Colombo
http://www.casacolombo.com/. It's kind of quirky, and not yet ready for prime time (they had a soft opening, but the website suggests it's further along than it really is). I'd try it for drinks and dinner and get a tour of the rooms before committing to staying there. It's very hip, maybe too hip for most of us... They are going to be hard pressed to get the room rates they're asking for with the worsening security situation. Also, they have no liquor license right now so it is BYOB... would have been nice to know that! Food was just ok, but it was a stylish outdoor space, hard to tell you were in Colombo.
Stayed in an ocean front suite at the Galle Face Regency and it missed the mark, even for a highly discounted local rate we got ($130). Spotty internet, rough finishing and lack of upkeep were the main issues. Restaurant 1852 was stylish and good food, I'd recommend it, which is surprising given the rest of the hotel misses the mark.