I've always wanted to do one of these, but here is my NFL Dream Team. Yes, it is huge, but NFL teams tend to be quite large (53 man roster). Here goes:
Offence (standard I-formation)
Quarterback: Peyton Manning in the regular season, Joe Montana in the post season.
Running Back: Barry Sanders.
Fullback: Jim Brown.
Wide Recievers: Jerry Rice, Cris Carter.
Tight End: John Mackey (there is a lot of talent for this relatively minor position, so I went with the best all-rounder).
Offensive Tackles: Anthony Munoz, Forrest Gregg.
Guards: John Hannah, Randall McDaniel.
Centre: Dwight Stephenson. Even though he didnt play long, I think he was better than Mike Webster.
Defence (4-3)
Defensive Ends: "Deacon" Jones, Reggie White.
Defensive Tackles: Bob Lilly, "Mean" Joe Greene.
Linebackers: Dick Butkus, Lawrence Taylor, Derrick Thomas. The first two are no-brainers, but the third slot is tough to fill. A good argument can be made for a few other guys, but I like Thomas the best. He was no LT, but he was an outstanding pass-rusher and a nightmare for opposing offences.
Cornerbacks: Rod Woodson, "Primetime" Deion Sanders (he is a must have, no team is complete without Primetime).
Safeties: Ed Reed, Ronnie Lott.
Special Teams
Kicker: Adam Vinatieri.
Punter: Ray Guy (this guy should be in the Hall of Fame).
Kick Returner: Deion Sanders.
Punt Returner: Gale Sayers.
Gunner/ST: Steve Tasker (another guy who should be in the HoF, no love for special teamers).
Formation based substitutes
Halfback: Marshall Faulk
Goal line/Short yardage back: Marcus Allen
Tailback: O.J. Simpson. Controversial choice, but I think people fail to remember just how great Simpson was because of all the stuff in his personal life. In his prime, the Juice was unstoppable even though he played on a terrible team. His breakaway speed is second to none (in my opinion, better than Bo Jackson) - the 90-yard rush against the Steelers says it all really (which is made more amazing by the fact that the Steelers back then had arguably the best defence in history).
Slot Recievers: Marvin Harrison, Steve Largent (both werent anything special in athletic terms, but they could play).
Dimebacks: "Night Train" Lane, Mel Blount (some muscle here is always nice).
General Substitutes
Quarterback: Dan Marino, John Elway, Kurt Warner, Johnny Unitas.
Running Back: Gale Sayers, Walter Payton, Eric Dickerson.
Fullback: "Moose" Johnston. Odd selection, but even though he played on a great team, he gets way too little credit. He was an excellent blocker (his blocking is a big part of the reason why Emmitt Smith is the NFL's all-time leading rusher) and he was a danger in both the run and pass game. Not bad for someone who occupied a relatively minor position in the modern game.
Tight End: Mike Ditka, Tony Gonzales, Shannon Sharpe (Shannon and Deion on the same team is too much to pass up).
O-lineman: Bruce Matthews, Jonathan Ogden, Walter Jones.
Defence: Ray Lewis, Jack Youngblood, Bruce Smith, Warren Sapp, Mike Singletary, Darrell Green.
Coaches
Head Coach: John Madden
Assistant Coach: Tom Landry
Offensive Coordinator: Bill Walsh
Defensive Coordinator: Vince Lombardi