I may be in the minority but I adored Medal of Honor: Airborne. I thought the campaign in that was fantastic, the fully open levels allowed for all sorts of playstyles. I've probably replayed the first level in that game well over 20 times, just trying out different ways to attack the same objective.
Granted, the game closed itself off little by little as the game went on, but that first level is still unmatched in freedom as far as how you want to play. The reboot was disappointing to me because it went back to fully linear gameplay. I hoped they would move forward, not back.