From 1985 regular season to present (1986 SB to 2010 SB)
Most Super Bowl Appearances:
6 - Patriots
5 - Broncos
4 - Giants
4 - Bills
3 - Steelers
3 - Cowboys
3 - 49ers
Most Super Bowl Wins:
3 - Patriots
3 - Giants
3 - Cowboys
3 - 49ers
2 - Broncos
2 - Steelers
2 - Redskins
Teams that reached Super Bowl in 80's, 90's, 00's:
Patriots
Giants
Steelers
Best Super Bowl streak (last 25 yrs) :
Patriots- 5 appearances in 11 years (3-2)
Broncos- 5 appearances in 13 years (2-3)
AFC East Championships (last 25 yrs) -
10 - Patriots
6 - Bills
5 - Dolphins
2 - Colts
2 - Jets (Pathetic)
I don't look at it that way and neither do most observers of the NFL. You're conflating too many periods with too many great teams. (And, it's five SB appearances in 12 years.)
Taking the 1985 season as a starting point (people usually talk of "seasons" when doing this kind of analysis, so the period you are referencing begins with the 1985 season), the Niners won three SB's between 1986 and 1994 and the Cowboys won three between 1993 and 1996. The Broncos, Giants and Redskins all won two each between 1986 and 1998. Saying that the Pat's "dominated" that time is just silly and more than a little embarrassing (this is the kind of statement that other teams' boards pick up, like we picked up the Jets prediction that they will go 15--1 this year).
There is no doubt that you can make the statement that the Pats dominated the 2000's with five trips to the Conference Championship, four trips to the SB and three rings. Only the Steelers with two Rings can even claim to be in the discussion, and then only briefly.
Your use of 10 AFC East Championships in 25 years in comparison with other teams is specious. Of those 10, seven came in the nine years between 2001 and 2009. The Bills won five between 1990 and 1995, a period of time that the Patriots hardly dominated.
I think the broader statement that can accurately be made of the Pats is that since the Krafts acquired the team in 1994, the Pats have become one of the premier franchises in the league. Then I think it's fair to place the Pats in the context of the history of the SB era by observing that only the Cowboys (eight) and Steelers (seven) have gone to more SB's and that only the Cowboys (five), Steelers (six) and Niners (five) have won more. I also think noting, as you do, that only the Pats, Steelers and Giants have gone to SB's in each of the preceding three decades is a good and fair point that can be made in this context.
Those statements would stand scrutiny and be accurate. Conflating a 24 year period in which many fine teams "dominated" at various times and saying that one team "dominated" the entire quarter century is just wrong.
Finally, to me the great unwritten story of this team is that Belichick and Brady have a chance to do what no other HC/QB tandem in the history of the SB era has accomplished: win a SB together in a second decade. That's where I'm focused.