Rivera is undeniably the best closer in the game. You can say Papelbon and Ryan are having better years, but neither have done it for more than 2 seasons. Hoffman is having a better year too, a career year for Trevor, but he's 2nd to Rivera as the best closer in the game. What Mariano has done is incredible. Not only was he un-hittable and ridiculously dominant in the 90s, especially in the post-season, he has also been the best and most consistent closer of the 2000s as well. You can say that a guy like Eric Gagne was more dominant for a period of time, and he was, but that only supports the argument for Rivera as the best of all-time.

Longevity-wise, being a closer is the most difficult position in baseball to survive and thrive in year-after-year. Gagne was the best for what, 3 years? Franky Rodriguez was un-hittable for what, 3 playoff series in 2002? Brad Lidge, un-hittable for the 2005 post-season until Pujols torched him, and now look at him. Don't even make me bring up Mark Wohlers.

Rivera consistently has an ERA in the 1s, often pitches several 3+ out saves.  In over 100 post-season innings, including 24 playoff series, only 10 earned runs allowed, only 84-freakin base-runners in 111.2 IP, that is silly.  That is as incredible an un-hittable as it gets.

Rivera's utter post-season dominance gives him an easy edge over an other reliever in baseball, ever.