This is somewhat map dependant, but usually I'll take
Light: Uller A until I hit Point Commander
Light: The Puma with 2 ppc/2mbl or 6mbl if its taking a long time to hit PCM
Medium: SCat A often until I hit Galaxy Commander
Medium: SCat Prime/Warhammer X if reaching higher ranks is slow
Heavy: none usually, though I'll take a Vulture A if the team needs long range support and/or getting to 92k+ cash is slow, sometimes a Madcat C or Prime for the same reasons
Assault: Mauler C if I don't have many c-bills, otherwise Madcat mk2 B all the way. If I don't have the cash to sustain assault mechs, I'll often go back to SCats or Madcats.
