I'm probably going to suck at specifics like issue but:
The entire scene in Green Lantern/Green Arrow #76 that sets the tone for the heavy stuff it would handle.
When Ganthet left the Guardians and joined the Green Lanterns as an actual lantern. Yeah, I had a nerd moment there.
The entire Mall-fight scene in the West Edmonton Mall. Just one of the most epic battles of the entire Alpha Flight run.
I can't think of any other ones at the moment