Aerotrek
http://aerotrek.aero/wingfold.htm
Remos (stabilizer is removable)
ICON
Fk9 (however, folding wings are optional, make sure you're buying it so equipped)
Kolb is probably the smallest, all things considered, because the tail folds too. It is also relatively short, because the pusher design allows for a short nose. Firefly can fit into a 20 ft enclosed trailer.
The dealer of Aerotrek makes a big deal of the folding wing capability, and indeed it's relatively well-refined. IIRC you don't even need to offload the fuel. However, the wings stay horizontal when folded and the tail does not fold. So, the airplane is very wide when folded. You must have the maximum permissive trailer (8.5 ft), and a suitable tow vehicle with tow mirrors.
Remos is the only plastic folder that I flew. It's quite slick. However, it is difficult to fold and reassemble alone. Wings are somewhat heavy and easy to damage. You better have a reassembly stand. On the upside, it can fit into a narrower trailer than most.