I will describe my list in terms of AS3 or UB2, though most teams appear on both lists at the same time
(coloured red)For UB2,
Kym & Alli (S25, 5th) : Strong FF team, only to lose because of failure in FF
Adam & Bethany (S25, 3rd) : Bethany proved the world having one hand is enough, but she is not able to put the cities in order
Hayley & Blair (S26, 3rd) : Hayley was always right, until the last roadblock which blew their win
Justin & Diana (S27, 2nd) : Dominating the whole race with 7 leg wins, only to lose it at the final leg
Tiffany & Krista (S27, 4th) : Having such a lead for the penultimate leg, only to struggled in the roadblock, cannot recover despite an hour log penalty of the other team
Tyler & Korey (S28, 3rd) : Winning the most legs, but fell short caused Tyler cannot jump a leap of faith
Brodie & Kurt (S28, 5th) : Getting teamed up by the other teams' double u-turn plan of the others justifying their existence
Becca & Floyd (S29, 5th) : Have them swapped the roadblock performer on their last leg, they may have a shot of winning
Henry & Evan (S30, 2nd) : Henry's second thought at the final roadblock caused them a million dollars
Kristi & Jen (S30, 3rd) : Hard to not include the strongest FF team ever in the race, right?
Alex & Conor (S30, 4th) : Over-thinking the signs in Lan Kwai Fong caused them a spot in final 3
Alternatives : Misti & Jim (S25, 2nd), Tanner & Josh (S27, 6th), Seth & Olive (S29, 9th), Matt & Redmond (S29, 4th)
For AS3,
Kym & Alli (S25, 5th) : Typical example of strong FF team
Adam & Bethany (S25, 3rd) : CBS loves to have inspirational role models in races (see Charla, Luke and the Cancers)
Hayley & Blair (S26, 3rd) : Not saying they fit the season theme, but they are arguably one of the most entertaining teams ever in race history
Jeff & Jackie (S26, 7th) : CBS loves show crossovers. Because Jody won TAR30, they are representing this time.
Justin & Diana (S27, 2nd) : They are representing the Super fans (urgh
)!
Tiffany & Krista (S27, 4th) : Who don't like some female eye-candies for the race?
Sheri & Cole (S28, 2nd) : The classic example of an underdog team. Would like to see how far they can reach by luck this time
Tyler & Korey (S28, 3rd) : Tyler's fame gonna keep them in returning, like Joey & Meghan
Becca & Floyd (S29, 5th) : Casual's faves must be invited to return, like Cowboys
Kristi & Jen (S30, 3rd) : The strongest FF team cannot be ignored, right?
Alex & Conor (S30, 4th) : Unique male teams relationship keep them in the spot
Alternatives : Shelly & Nici (S25, 7th), Matt & Ashley (S26, 5th), Denise & James Earl (S27, 5th) Burnie & Ashley (S28, 4th), Logan & Sara (S29, composite 3rd / 8th), Matt & Redmond (S29, 4th), Trevor & Chris (S30, 7th)