(High)G C E A seems to be used more than ADF#B from what I see on the net.

@Guest Grishka: Yes, the UOoGB do seem to use various sizes and tunings (sat in the first row of one of their concerts once) but this is just the case with other players (over here the flat tenor model by Kala seems to be popular), but the UOoGB insits that the big thing is a bass ukulele because it has four strings like a uke while guitars have six strings...;0)

Now the aforementioned Kala company introduced a real bass ukulele (bariton size with fat plastic strings - sounds like a double bass when played amplified)