Mostly micro armor. GHQ have great models that are very inexpensive
considering the cost of most larger scales. I play a ruleset
called "Ambush Blitz" by Jerboa, The rules are not widely played, but
is a great set of rules for quick play. The game lacks details, but
not polish. The after action report of the game usually sounds like
an historical battle AAR.
In addition, we play Gladiators in 25mm. The figs cost a few bucks a
piece, but one needs only a few for a great game in a scratch-built
coliseum. Home rules again, "Minimus Maximus"
Pirates are a favorite of my kids and me both. We play home rules
called "Wooden Ships and Wooden Men," using homemade 15mm wooden men
which are modeled roughly on the shape of lego toy people. Hey, this
is the ultra cheap miniatures gaming group, after all.
I have a pretty extensive collection of Napoleonic ships in 1:2400,
which I game with using home rules called "Gun to Leeward."
Jim