Ahh.. then they might also want to hit the EMP
http://www.empsfm.org/index.asp
and as far as Cobain goes..
The house he died in.. 171 Lake Washington Blvd. E
The park next to it is where his ashes are scattered.
http://thecrocodile.com/index.html Club that was the center of Seattle grunge for years.
if they want a late night greasy spoon... Beth's Cafe (Okay I'm partial to the name)
http://bethscafe.com/ 24 hours.. features a 12 egg omelet served on a pizza pan. Has been featured in alot of tv shows. Very grunge.