Then i'll suggest some of my favourite that first come in my mind, trying to avoid the most obvious:
- Lines in the sand (long one though)
- One last time
- Under a glass moon
- 6 o'clock (this is probably interesting since the drums rhythm here stands out)
- In the presence of enemies part 1 (maybe it's a bit long, i don't know)
- Prophets of war
- Erotomania
- Ytse jam
Anyways, talking about DT i've just seen them live here in Rome.
Awesome concert! Everyone did his own solo (yes, even John Myung!), they inserted a cool excerpt of Enter Sandman in "As i am" and eventually there was a nice surprise at the encore (not gonna say it in case you're going to see them live in this tour) 
I could start off with Erotomania, I think it's a remarkable song and quite challenging as well I must say.
Heh yeah I'm going to see them on 27th, can't wait. I've actually looked up the songs they've played so far on the tour and seems like Change of Seasons is the encore! And Images and Words as a whole just before that.. Oh boy 
cool, looking forward to it then!
Yeah, i got close the stage at the end of Images & Words, but then they started playing A Change of Seasons
so we all stayed there and i was lucky enough to grab one of the plectrums that John Petrucci threws at us!
