There are, of course, a number of drummer-less groups with varying instrumentation that we can check out, but if this is a new concept to you, I'd start at the beginning with the first great drummer-less trio: that of Nat King Cole. Nat, along with bassist, Johnny Miller and guitarist, Oscar Moore, don't need no steenking drummer. These are some of the swingingest recordings of all time.
Here's one to get you started, but I recommend just trying to lay your hands on as much of this stuff as you can. Even if it's just one of those greatest hits records that you can snag for 3 bucks.