Modifying your original terms:
Size: 2-3 quart/liter. I consider 2.5 quarts to be ideal.
Material: Two options: hard-anodized aluminum nonstick, OR stainless-steel interior/exterior. With stainless, it should have either an encapsulated aluminum disk base or a tri-ply construction (aluminum layered with stainless)
Bottom: Thick is good, and you absolutely must have aluminum here for conduction
Handle: stainless is good, as long as it stays relatively cool. The handle absolutely must be riveted on, with thick rivets. Screws, glue, or welded handles do not last long-term. Tack-welded handles are the bane of the restaurant I work for right now; we've had several handles snap off in the last year.
Additional things to look for:
Weight: HEAVY. You want fairly thick cookware for even heating, but most of that weight should be from thickness of the aluminum disk.
Design: A flared lip around the pot, to facilitate clean pouring.
Shape: I'm partial to shallow designs, which flare out at the top. Although it's nonstick and not stainless, I love my Calphalon Contemporary shallow 2.5 qt saucepan for it's extra-flared design. This lets it transmit heat more efficiently from the range, and allows it to safely hold a larger capacity of food. It also allows for faster and cleaner reduction of sauces.
Lid: TEMPERED GLASS with a handle on top, and a flange to help seal tightly on the pot/pan. Tempered glass is very durable and lets you see the progress of your cooking without releasing the steam. The handle also remains cool, so you don't burn yourself on it; this is the second problem I have with solid stainless lids on many premium cookware lines (All Clad, and most manufacturers' tri-ply products).