TAR's best routes in my opinion are:
Season 3 (Scotland, Portugal, Germany, Austria, Switzerland and Vietnam)
Season 5 (Argentina, Egypt, Tanzania, UAE, New Zealand)
Season 6 (Iceland, Norway, Sweden, Senegal, Hungary, Corsica, Sri Lanka and Xian)
Season 12 (The Netherlands, Lithuania and Croatia)
Season 22 (Bora Bora, New Zealand, Indonesia, Vietnam, Botswana, Switzerland, Germany and the UK)
Honourable mentions for:
Seasons 15 and 18