Single bowl appx. 20" x 30" overall (including deck) and 8" deep, with disposer in the center. It dates back to the early '70s and is in great shape. I'd never have anything else.
When we remodeled the kitchen at our previous house, we wanted a sink with five holes in the deck. At the time, single hole faucets were not approved by city code, so we needed three holes for the faucet, another for an instant hot water dispenser, and another for the dishwasher air gap. The only choice was an American Standard double bowl model. It didn't take me long at all to hate working within the confines of two bowls, each less than half the size of a single one, and I will never have that type of sink again.
If/when we remodel our current kitchen, I'm inclined to save the sink and reuse it in the new scheme. I haven't seen anything new out there that's comparable. I just wish I could find protective sink mats that fit it. Right now I'm using two mats that fit double bowl models, which leaves the disposer in the middle accessible.
We considered stainless steel when we remodeled at the other house, but at the time I worked for an HVAC contractor and one of the plumbers there warned me that stainless sinks have a tendency to "act like a speaker" when the disposal is in use. That was enough for me to rule out stainless.
Also, without a doubt, an under-mount or flush-mount sink is the only way to go. The double bowl Standard was a drop-in, and wiping down the counters was a PITA having to go up and over that giant lip. Never again.