mesa tripple recto head has the best distortion ever.
at least in a self-contained unit.
you also have to realize that watt-for-watt, tubes are much louder than solid state equipment. my 125 watt tripple rectifier will completely slaughter my friends (400 watt i believe) line 6 head. his head sounds great, dont get me wrong, but when playing in an un-miced enviornment, the tube amp will kill it.
his amp also sounds good, but not as good as the recto. its even got a recto emulating setting. it sounds really good, but against the real thing, its just not all there.
but then again, his amp comes with built in effects and cost half what i paid for my head... not including all the effects and cables i own to get my setup, and the tubes i have to pay to replace every couple years.
on a budget or if you dont want to deal with the maintenance, solid state heads are the best. but if you dont want to compromise sound quality, most people go with tube heads. especially in rock music. look at a lot of the hot bands of today. marshall & mesa reign supreme, and for good reason.
but then again theres people like dimebag from pantera who have used nothing but solid state from the get-go and have amazing sound as well.
but i think given the choice and unlimited funds, most people would snag a tube amp for at least part of their sound. but i may be biased, i was raised in a home filled with tube amps, blackface fenders and kustom tuck-&-roll setups.