Houston is a team I see having made big strides. ND Kalu, Anthony Weaver, and Mario Williams should provide sufficient pass rush to rattle Manning from time to time, and give them a chance against the Colts. Moulds adds a necessary 3rd weapon to the offense, and Putzier while still mediocre in my book is an upgrade at TE. Flanagan and rookies Winston and Spencer should make a marked difference in that line, and most of all, I love the coaching change choice. When considering this year's class of rookie head coach's, Kubiak looks the most impressive.
Cleveland is the other team. Jurevicious gives them a solid veteran WR, but mainly Schaffer and Bentley make that o-line loaded with talent. McGinest made for a very nice defensive leader to add with all their young talent. This team may still be a year away, but Crennel is looking like he'll end up winning coach of the year in the next 5 years.
Denver didn't make as much improvement, but I feel Javon Walker's presence is being underestimated. This team is a legit Superbowl contender if Walker is healthy. The Giants quietly added Arrington and 3 quality veteran DBs to eliminate any weakspot on their team. But Cleveland and Houston are definitely the offseason's top winners. Of course, when you're that far down, its a bit easier to improve.