I collect mostly the 3rd gen, with a few of the Friendship is Magic G4 ponies thrown in (the unicorns and pegasus). I don't really like the regular 4G ponies with the extra-big heads. They're too ... cutesy for my tastes. And the G2 ponies just look ... deformed.
Oh! I also have one remaining G1 pony. A special pearlized mail-in baby unicorn that fanclub members could buy. The rest of my childhood G1 collection has disappeared into the abyss of time.
That, or Goodwill. lol