Speaking of Elgar, if anyone can get hold of his Symphony no. 1 in A flat, do so. It's stirring stuff.

(Incidentally, I've always imagined the entire symphony as a musical interpretation of the original Star Wars trilogy [or, rather, the films being a motion picture interpretation of the symphony, of course] - listen to it and you might feel the same way too.

)
Also spine-tinglingly full of hooks is Gershwin's Piano Concerto in F - not as well known as "Rhapsody in Blue" or "An American In Paris" or his "I Got Rhythm" variations, but it's my personal favourite Gershwin piece.
Ah yes. Variations. The best of which by far are Brahms's "Variations on a theme by Haydn" (arguably the first "remix"?

) and Rachmaninoff's "Rhapsody on a theme by Paganini" (my all time favourite piano/orchestra work - and the Paganini original is in itself a masterpiece of violin virtuosity).
I'm a sucker for piano works, since they tend to have lots of hooks. Beethoven's PC 5 'Emperor'; Grieg's of course;
I like the ELO version of Grieg:
http://www.youtube.com/watch?v=LQ8oMav1Yq8
Tchaik PC 1 is perhaps the definitive hook music of all time
... best heard in the original Monty Python:
http://www.youtube.com/watch?v=dvpALlP_7lE
and Rach PC 2 if you're trying to romance a ladeee.
Sadly, all my attempts at such a feat have been but a Brief Encounter, leaving me All By Myself in the end.
Although speaking of Rach, his Symphony 2 has a lot of neat hooks throughout (apparently all based on one main long theme, which I never really got into) as well as some shamelessly sentimental moments - listen to the third movement and cry.
And, of course....
Sibelius 5... 