I've been obsessed with Dadd9 lately, because it sounds great on my baritone ukulele and I can go to so many different places from it. (I guess technically on the uke it's a Dsus2 (0230), since I replace the 3rd with the 2nd.)
Try 4230 on your baritone ukulele, a Dadd9 with the 3rd on the lowest string. Sounds nice on my tenor guitar (tuned d-g-b-e like a baritone ukulele with steel strings).
Add9- and sus2-chords are two of my favourite chords at the moment actually:-)
I am noodling around a progression that goes like this:
0022 (G5) 0230 (Dsus2) 2030 (Em7) 2002 (Emadd9)