I would second Fermier and add Thompson as well. As an ENTC grad my classes revolved around these buildings. Fermier is horribly designed, and has that "two-person elevator of DEATH".
Thompson has been through hell. It is constantly being remodeled/retrofitted. Last semester i was there (Spring 04), a stairwell was sealed to extend an office on one floor with the stairs remaining on the lower floor until it was made into a closet. For a few weeks, they were adding extra support beams in the basement/lower floor. There are other doors/stairs leading to nowhere or the roof. There is one door on the roof labeled at one time "solar lab" that was seen across a window from one of the labs. We wondered if we had to get on the roof to access that lab. The numbering system is totally weird.
Of course that is ENTC and ID for you, off in our own little world from the rest of the engineering depts.