Allen has good range and displayed an ability this year to make big plays at key moments. Allen is not adept in single coverage situations but he's become far more aggressive than he was in college and has improved markedly as a tackler. Allen doesn't have great size but he is an exceptional athlete.
Hats off to Dexter Jackson, who had a really good run in Tampa punctuated by a Super Bowl MVP award for his two interceptions returned for touchdowns against Oakland. Over shadowed by other big names on a great Bucs defense, Jackson saved his best game for the biggest stage. If I could have a career like Dan Marino (great stats, no Super Bowl rings) or Jackson (less impressive stats, but a Super Bowl ring) I think I would take Jackson's career.
EDIT: I'm an idiot, thanks to Tampa in 07 for pointing out my mistake, Jackson had two interceptions but did not return them for touchdowns. I was thinking of Dwight Smith.