There haven't really been that many jerseys. By that I mean actual mains, as teams change up thirds and use one-off specialty jerseys regularly these days.
http://www.nhluniforms.com/Senators/SenatorsNEW.html
I count three distinct periods
1. from 1992-1999 was the golden age of ottawa senators fashion, there were minor changes with the white bar being added and number colour changed on the black jerseys but overall things were fairly consistent. towards the end of this period the terrible red "swoosh" jerseys were introduced as the team's alternate jersey, complete with silly cartoonish logo.
2. from 1999-2007 the team phased out the blacks and went with red swoosh as full-time mains along with the original whites, using two different logos which was really weird. the latter end of this period saw the black & gold alternates using the swoosh logo instead of the classic abstract one, a dark omen which signified the impending doom of the classic logo by a corrupt cartoonish force.
3. from 2007-present the team has worn an awful default reebok edge layout with a new logo that mixes in the angle of the cartoonish one with the flat white style of the original. a slight upgrade on the swoosh logo but still a subpar logo. during this time the team has used two alternates, the black "SENS" abomination as well as our Lord and Savior the heritage Os.
you could even count the middle period as half a period since they still used the original whites, only half the getup was changed