I'ld definitely pick Geos ... 'cause they're fun and have a lot of utility.
They are very easy to gear compared to a lot of the other teams, and they make a decent team in fleet.
In GAC they punch above their weight... yes they can be beaten by a 2 man Traya team, but if you opponent feels confident wasting Traya on the Geos, be my guest.
Yes, they can be murdered by that horrible Jawa Scavenger bug, but chances are your opponent won't get many points for it, as there will only be one or two toons left on the team, and they will not leave with full HP and protection.
As for the other teams:
501st Clones would also seem to be a great choice but those buggers are gear hungry when you want to go beyond G9.
Padme GR is also a great choice as they will be needed for the LS Geo TB (the 501st will also be needed, but again... gear crunch...). And they beat most other teams.
GG is also a very relevant team, but they need to be G12 to matter - and GG needs to be G13, so maybe work on him first. And once he's G13, consider gearing the other droids.
Also: Consider getting your FO or Resistance topped off (do you have 7 stars on Rose?). They may be needed later this year and you don't want to be caught in a panic farm.
