I think Guero is a really good album, it's more consistent than say Mellowgold. Mellowgold would have some of my favourite songs on it, but it's not as consistent as other Beck albums. It's tough to pick a favourite Beck album for me.
As for his lyrics, I don't necessarly find them funny. Sure they're witty, and some lines can make you smirk, but to call them funny is to call them stupid, and they're anything but stupid. He writes great abstract lyrics from a stream of consciousness. His music (lyrics included) are always interesting, which is few and far between when it comes to musicians and artists in general, these days.
I want girls with new-wave hair-doos