Best integrated for rock music under $1,500?

The Nad is good I echo Ekobesky on that. The trick is to get a real powerful amp. I owned Aragon Monoblocs. They are still under Klipsches roof but aren't making amps anymore I think you should consider the older NAD power envelope amps.
Also a Sansui made seriously good amps. I know I have one that is supposedly 85 watts but sounds much more powerful. You can pick up a AU-717 for nothing maybe $200. If your OK not having a remote they are good. If they break and you need a part you might as well toss it or sell it for parts but I have used mine intermittantly for 3 years no problems.
The Aragon 8008ST is the poor mans Krell. You can even get the 400wpc Palladiums I had but you will need a preamp. You may want to think about it. These amps will power the cones out of the frames if you want.
Finally the old MacIntosh amps are unreal in terms sheer slam if that's your goal and my little 2505 drives anything and it is rated at 50 watts. The integrateds are not expensive used. The power amp of choice in the sub $1K price point is the 2105 rated at 110 watts per side again as a rule the bench over that. They have gain controls so if you use one source you can adjust the volume. The more you spend the bigger the amp. You can get historical information from www.roger-russell.com it is not a commercial site he is a former employee.
There are some pro amps that people consider musical . Check those out you can buy a pro amp for $1500 that has 4,000 watts. Do a search!

Yes Sansuis are truly fine amps. They are usually old and could be improved if the caps are replaced etc. However if you have any doubt look at fleabay for the BA 2000 or 3000 these are the straight power amps same vintage as the AU series even the CA preamps fetch some money.

I recently followed an auction for a circa 1977 BA 3000 Sansui power amp. not the integrated. It fetched over $3,000. Sansui was a premium brand it was more High End sounding before High End became a phrase. I have to tell you that their old tuners are still considered amongst the best ever made and are compared with modern tuners on a regular basis on the tuner info site. Beyond which one of my amps is an integrated tube amp vintage 2003. The circuit is the "Mullard Long Tail" which was developed in 1922. This is not a replica it's just a new version of that circuit . Anyway shell out $200 for an AU 717 and see. I ask you this do you think a 25 year old KSA 200 pure class A Krell is a bad amp?