Good Groups to Cover with a Ukulele?

After a few years of playing the uke and collecting songs for my "repertoire," I'm finding that the pool of material that lends itself to this instrument is drying up.  With the exception of Jason Mraz' "I'm Yours," there hasn't been a "new" song in a while that I immediately thought "I've gotta learn that one," so I'm constantly revisiting all the oldies catalogs to find songs I may have missed.

At this point, while my song list includes stuff from hundreds of artists, I find that the majority of the list is from The Beatles, Jimmy Buffett, Fats Domino, and a bunch of one-hit country artists.

I wonder if there is a group I have overlooked that might provide a whole new flow of songs to learn.  Any ideas?

(PS:  I'm not really looking for individual SONG ideas, just groups with many songs that are suitable for the soprano uke.  Also, I'm not a great singer (Beatles are fine/Stevie Wonder is not), so it needs to be a group whose songs do not include challenging vocals.  Finally, I do not gig on the uke in public, so I'm not necessarily looking for crowd-pleasers.)

Thanks!