i have a 95 gt legacy. when i got home today i noticed some smoke coming out of the left hand side of the engine bay...what could this be?????

oil more than likely. Was it coming from the exhaust pipe or the engine? What color was it? Maybe someone did an oil change recently and spilled some oil on the engine, the oil fill thing is on the drivers side of the engine.

Check to see if your CV boot(s) are intack. Mine recently broke open and slung grease on the exhaust and cooked nice and hot with lotsa smoke.

It could also be oil from the front differential breather, this can make it to the exhaust if it spits oils for any reason.
As mentioned above though, check the CV boots too.