I live in Galway so I haven't actually stayed in any. To keep away from noise, keep clear of Park House, Imperial, Jurys, Spanish Arch, Victoria, Warwick.
The Great Southern in now owned by the same guy who owns the G Hotel; it was completly refyrbished last year but I haven't set foot in it. It is now called The Meyrick. It is in Eyre Square. It looks lovely when I pass.
How about Salthill? Galway Bay Hotel is great. Next door, Salthill Hotel has been rebuilt and extended (although it's not finished at the moment, it will be ready for next Jan)....it will be classy.
Days Hotel is about 4km from city centre.
In city centre, I suggest Radisson or House Hotel.