Ghee.. With that list, which I must say is no where near the cream of the crop in those areas. My opinion with that list, Dream Theatre would come out on top. But metallica wouldn't be very far behind. Like Rask said, dream theatre definitely is better in the technical (musicianship) area but when it comes to songwritting metallica has more classics. Well before they got to be pu$$ies. hehe.

If your to balance them both, Pearl Jam and Alice in Chains would be well balanced in both. Neither one were true virtuosos, and neither one had a great deal of songs that would considered great songwritting. Nirvana was terrible in the area of musicianship, anyone who has actually seen them or even live footage knows that Kurt would purposely throw his guitar out of tune, or just not even play the song right. Even the unplugged album is loaded with mistakes, not something you merit true musicianship with. Although in songwritting, many of nirvana songs will go down as classics. There songwritting skills were near genious. Audioslave just hasn't been around long enough, and neither Rage nor Soundgarden can take a top seat in either category. Although I do rock out to both. :)

Now the best without the list. As a band, it would be a tie between The Beatles and Led Zeppelin. I choose these two based on being the best in both categories equally. That's my opinion.