Vitalogy is also my favorite PJ album and Yield and No Code are also right up there for me. I like a lot of their later stuff as well. Binaural is awesome. I'm not much for greatest hits collections, except to complete a collection
. I hardly listen to them.
For Soundgarden, definitely get Badmotorfinger and Down on the Upside. I like everything Soundgarden and PJ have put out, pretty much, so I'm sort of biased
...
I can't pick which is better for me, as I like them both. I think Eddie Vedder is a superior lyricist, though. His stuff is amazing. That man can spin a yarn and then some.