Not sure abut everything in the Action Fleet range (although they are the nicest models), or Micromachines - eBay will help you go through them. The Titanium diecast series throws up the occasional surprise, but the pack size is fixed so don't expect too much. There's also the De Agostini series of magazine diecast models, of which I have no experience. My collection has the following:
Hailfire Droid - WotC one is good
Octopturra- got one in a bigger scale from Hasbro
Dwarf Spider Droid - WotC
Crab Droid - WotC
IG-88 speeder - WotC may be your only choice
Republic gunship - Transformers one is OK but small, Revell kit is not quite as small (1/72)
Republic Assault Shuttle - the Revell one is too small (1/100) but works as a piece of terrain
BARC speeder bike - WotC do one, De Agostini also have one but no idea of scale
AT-RT - WotC is the only one in a decent scale
Swamp Speeder - WotC one is good, Titainium diecast is way out of scale.
AAT tank - Revell kit is good, Transformers one is OK too
At-TE - Revell Kit is good, Transformers one is way too small (could do as a mini version)
Clone wheeled tank - everything I've seen is far too small
Snowspeeder - Action fleet is great, there are a couple of variants. Revell EasyKit is also good
Rebel Speeder Bike - WotC, Micromachines do a set as well
Imperial Speeder -WotC, Titanium diecast one is OK but rider is too big, Micromachines do one as well
AT-ST - WotC do a couple of versions,, Imperial Assault one is good
AT-AT - Revell kit, WotC one can still be found on eBay, Micromachines one too small, ERTL kit - not idea about scale
Dewback - Titanium one is a bit small
Sail Barge - not much I know of
Skiff - think there may be an older one kicking about that's OK - Kenner? WotC do one too