Tasks: TAR 25
Some of the Detours at TAR 26 were really unbalanced, ESPECIALLY the first leg (Samurai Sake looked way easier than Syncing Steps). TAR 25 also had some memorable tasks for me, like the punting in UK, Roadblock in Denmark, Flag Detour in Malta, and the final Roadblock at the final leg.
Route: TAR 25
Of course TAR 25 has the better route than 26. Other than new visits to U.S. Virgin Islands and Malta, the locations visited are either never before seen or haven't been visited for so long. Yeah, TAR 26 has Peru and Namibia, but another visit to Tokyo, Bangkok, and Amsterdam was boring for me.
Teams: TAR 25
First, TAR 25 had all-female teams, which what TAR 26 really lacked of. Then, TAR 25's teams are (I think) equally competitive and more variant while TAR 26 lacked of competitive teams, other than Laura & Tyler and Hayley & Blair. Some of the TAR 26 teams are not really memorable for me, like Jeff & Lyda (I don't remember them at all), Libby & CJ (I only remember them missed the train to Nagano), and Aly & Steve (these two were overshadowed by the remaining blind date teams), while ALL the teams on TAR 25 have their own memorable moments.
Drama: TAR 25
TAR 26's dramas are mostly intra-team, not inter-teams. We didn't see any drama on Mike & Rochelle IIRC, but on TAR 25 the dramas are so many! From leg 1 we had seen a drama between the firefighters and the realtor sisters, then we saw the drama on the way to Pit Stop at leg 2, don't forget leg 5 drama between Shelley & Nici and Keith & Whitney leading to the U-Turn and Keith & Whitney's elimination, and then the drama between Brooke & Robbie and Amy & Maya from the Singapore leg until the final leg (remember Brooke & Robbie's reaction seeing Amy & Maya at Manila Airport on the final leg?).
Fun: TAR 25
I think TAR 25 wins simply because of the previous season (TAR 24, ew). After watching the worst TAR season ever and then seeing TAR 25's teams, routes, tasks, and locations, I'm always anticipating what's coming next week. However, TAR 26 came after TAR 25, where my standard and hopes are high, but actually it didn't deliver as much as I expected. The thing that make me still want to watch TAR 26 was Hayley & Blair and that's it. When I watched Hayley messed up at the Roadblock on the final leg, I immediately skip the rest of the episode until when Hayley & Blair reached the Finish Line at 3rd, that's because I just lost all my fun and excitement watching the finale leg.
Overall: TAR 25 wins all the way!