I think one of the biggest determining factors for me will be the tone/vibe of the planet.
For example: music, aesthetic, local fauna, and things like that. If all those factors combine into a friendly/inviting/upbeat atmosphere then I'm a lot more likely to want to colonize it and spend a lot of time there.
But, I guess it's possible that most of the planets could feel pretty similar. In that case, I want to colonize a frosty planet, a swampy planet, a SUPER HOT planet, etc.