borneo since its the original (most people who watch it after being familiar with new seasons dont like it)
pearl islands
vanuatu
guatemala (only 2 returnees from the previous season)
for the newer seasons id say
gabon
san juan del sur
GABON. Aka season 17.
That was one of only two seasons I have seen that I was able to stay interested enough throughout it's entirety to not just check wikipedia to see who wins and move on to the next season. There are a lot of interesting personalities and the final 6 is really not what you'd expect just based on first impressions. I recommend it. Let me know if you need a place to watch it online!