Do you have any all-time favorites in these categories? You don't have to list by season, just put any that come to mind.
My favorite roadblock was in season 1, when the final 5 teams had to go through the temple of rats (I think this was in India). I'll never forget Margarita, with that look of determination on her face, never letting the rats affect her. My second favorite was in early season 3 (I think they were in Scotland or Ireland) when one team member had to throw a shot put and do other things. This cracked me up because Teri agreed to do the task, not realizing what it was, and then Ian was haggling her all the way as she tried to finish the thing in peace. I also liked the mask roadblock in season 4/episode 2. Of all the detours, the one I enjoyed the most (at the time and looking back) was Cha Cha Cha running through the streets in their dragon costume. Another good one was Gutsy Grannies meeting the woman on the beach in Brazil. One of my favorites in season 3 was rowing in the gondola, because Ken and Gerard kept falling out of the gondola, laughing and bowing to the reactions of the locals watching.
Fast Forwards: The orangutan FF with Reichen and Chip is the one I most clearly remember and enjoyed, probably because of how lighthearted the task was. For sheer coolness, the one that sticks out is the FF the father and son got in season 3. Driving around in the tank, then being escorted to the pit stop in a limo (too bad they got there in last place though).