In the past, I've done Dragon Pass, Balazar and Dorastor.
Currently, I am doing Pavis/Prax, but using RQ3ish rules (RQ3 with some RQ2, some RQM and some house rules).
All in the Third Age, as my players aren't comfortable with the Second Age yet and want to finish the current campaign first.
The Second Age background looks good, but there just isn't enough scenario material out there just yet to do a full campaign. Maybe when Blood of Orlanth and Clanking City come out, this will change.
Rune of Chaos just doesn't cut it, I'm afraid.
I suppose any area where Jrusteli and EWF collide would be good Second Age settings. The Shadowlands is the prime example, as it borders both empires and has the Clanking City nearby.