I was thinking that there should just be a thread discussing what some simlish might mean or any simlish that sounds funny. Here are some that I find:
"Wippna chobba dog!" (when they hop, clap, and move their fist down; occurs when sim is excited. Possibly means "Yay, I like this!")
"Blarg! Has chuu, ugh!" (when sims complain that there is no "route" to an action in the queue Possibly means: "Hey! I can't go there; ugh!")
"Aww, nebba nooboo" (Cooing to babies, of course. Means "Aww, sweet baby" I think)
(I did find a thread like this, but it hasn't been posted on since September, I think.)