There was Metallica's last tour (as mentioned).
Kamen also did orchestrations for a tour in the '90s where Roger Daltrey (and some bizarre guests like Sinead O'Conner and Linda Perry (4 non blondes) ) did Pete Townsend songs. Most Who fans panned the series, but the orchestrations were brilliant.
Yes put out some symphonic albums that are quite good.
Renaissance is one of the best 70s "powerbands" ever. They usually played with an orchestra. The songs are innovative, and Annie Haslam's 5-octave (or was it 7?) vocal range is pretty astounding. I highly recommend any of their live recordings.
Mike Oldfield had a little bit of probably synthesized symphonics on Tubular Bells III and The Milennium Bell. Good stuff on Voyager and Symphonic Tubular Bells as well.
And don't forget The Moody Blues.
Quite frankly, though, if you want incredible orchestral music, look no further than the great nation Hungary where classically trained musicians play hard rock.
Good names to check out:
Solaris (and flautist frontman Kollar Atilla's solo album "Musical Witchcraft" which features most of the Solaris lineup anyway).
After Crying does some of the most amazing stuff I've heard.
Rumblin' Orchestra (2 albums: Spartacus and Kings New Garment) are essentially the demon spawn of After Crying and one of my favorite Hungarian groups. Be forewarned: After Crying sings in Hungarian. Rumblin' Orchestra sings (not often) in English that is so broken it might as well be Hungarian
I think East might be a good choice, too.