Duke Senior, Shylock, Henry IV, Leontes, Malvolio, Macbeth, King Lear, Orsino, and the occasional Dogberry are my current go-to Shakes monos. Not sure how I feel about 'em. The most difficult one for me is Dogberry, so I do it only in a pinch. Leontes is also tricky but he goes deep for me so I keep swatting away at him. I'm going to work on some Claudius and Petruchio, as well, and maybe brush up some Holofernes, whom I love. I need to rotate between enough monos so I always have something in the pocket with which I'm not too comfortable and makes me a little nervous to do.
The contemporary pieces I'm rotating are Roma, Roy Cohen, Johnny (Frankie & Johnny in...), Christy (Lieut of Inishman) and the occasional Midas. Gonna add in Hook, Lockhart, and Alfieri, which I haven't done in awhile. I'll do them better now. Dialects I'm least embarrassed to trot out are Dublin(ish) Irish, RP, and a soft R American Southern; a NY dialect too often alludes me, probably because I'm the kind of guy who says, "alludes me."
I have two on camera sides I'm currently doing but am keeping an eye out for more.
Actually, don't need the monos that often, any more, usually only for EPAs, which I hate and mostly avoid, and the occasional citywide open call, which I enjoy.