I love RUSH. That is about 80% of my listening. Sad perhaps. On one of the fan blogs they will have comments by members about other bands sometimes, or Alex or Geddy will be working with a band. Then I’ll go give them a listen, and some of them are okay. Dream Theater and Porcupine Tree I listened to for a little while, but they really don’t hold my interest for too long.
Hmm. You might want to give Kamelot a listen, or maybe Nightwish.
As someone coming from basically the same place and looking to fill the void Rush's retirement left in our lives, I recommend you check out Coheed and Cambria. They are a little rougher-edged than Rush and in their 40's now, but the songwriting is much better than Dream Theater (though DT always wins for musicianship) and you can hear the clear Rush influences, especially in their earlier science-fiction-themed work. They are a little more pop- and or metal-sounding at times, but the cleverness and creativity of Rush are there.
Also, if you like instrumental work, check out Arch Echo and also Plini. As a guitarist, those two are who I am listening to a LOT, lately. :)