There's always the tried and true GAP Adventures (in Ontario) at http://www.gapadventures.com/

I did a quick search on thier "comfort class" trips to Europe (only two in comfort class), one of which goes to Paris, Dijon, Burgundy vineyards, Nice, Villefranche, Monaco, Cinque Terre, Florence, Rome.

Then thee's Elder Hostel and Elder Treks, but they're somewhat pricey.

Nadine Vancouver