I use Lexol Leather Cleaner (orange bottle), not to be confused with Lexol Leather Conditioner (brown bottle).
For conditioning, Lexol brown might darken light colored leathers and avoid anything with either mink oil or Neat's foot oil as they will make the glove heavy.
Nokona has a new conditioner I have not tried, but the standard Nokona NLT is just Vaseline, as is the Vinci conditioner. Vaseline makes a pretty good sealer to hold moisture in (some say it clogs the pores, but I don't think it causes any harm). A light coat at the end of the season before getting put away would be a good use. But if the leather is dried out (e.g. been sitting in the attic for 3 years) and needs to be "fed", then Wilson Pro Stock Conditioner, Mizuno Strong Oil, GloveStuff, Lexol brown, etc. are all good.
On a new glove, very little should be needed. I sometimes add a little to the hinge/pocket as I try to break a glove in, but after that I have found that less is more.