Depends on which rod/method I'm using ... but, Vicious Panfish 6lb test hi-vis is my current favorite for jig casting.

If/whenever I run out of what's left of the 1/4lb spool I have ... I'll consider calling CARP Coastal Marine Supply 321-592-1303 and see if their listed price of $5.69 for the 1/4lb spool of 6lb test is still viable. They have a "minimum purchase of $7.50" ... so I'd have to buy two spools, but that's still cheap (as long as the shipping costs are reasonable). Vicious PYLQ6 Panfish Mono 1/4lb - 2360yds Hi-Vis Yel - Carp Coastal Marine Supply