1998 Toyota Camry XLE, 164,000 miles - rough idle when stopped

The idle on my Camry is too rough. When I'm stopped at a light, whether or not the air conditioner fan is running or not, I'm experiencing a rougher than usual idle. It's like it cycles through a rough idling period-- while stopped it becomes very rough, then a few seconds later smooths out again, then becomes rough, etc.

In the last month my car has had a lot of regular maintenance plus a few extras repairs outside regular maintenance. There is no engine light on as well.

They are:
Tune-up including all spark plugs replaced
New oxygen sensor which is attached to the catalytic converter
Four new engine mounts-- the original were shot
New struts-- the originals were shot as well

The car is a very good car, and runs well except when stopped.

Can you help?