As mentioned above, the important factors are whether you just want to boil water or whether you actually cook. Another factor is the fuel efficiency of a short and squat pot vs. a tall skinny pot. A third, not yet mentioned, is whether or not you camp in winter when you'll be melting snow for water. A 4th is whether you go solo or will be preparing meals for 2 or more.

I strictly boil water, go solo, and do not winter camp. I get along fine with a 500 ml Ti pot, 2.0 oz. including lid. This gives me enough boiling water to rehydrate a dehydrated dinner in a freezer bag and make a cup of herbal tea (which I brew in and drink from the pot while my dinner is rehydrating). My dinner servings are relatively small, so if you get really hungry, a 750 ml or 1 liter pot might be better. If you want to wash yourself in the leftover warm water after dinner, definitely the 1 liter pot. (You probably don't want to wash in cold water at bedtime!) In this case, you really need a cup for your tea, since you don't want to smell of peppermint or camomile tea to passing bears!

If I'm fishing, I also take a 4.2 oz. frying pan, which I consider part of my fishing gear.

If I were going to cook meals from scratch instead of rehydrating, I'd take anodized aluminum which spreads the heat much better than titanium, and I'd take both a cooking pot and a frying pan. Hopefully the frying pan could be used as the pot lid. If you're cooking pasta, you really need a 1 to 1.5 liter pot so it won't boil over.

If I were going to melt snow for water I'd want at least a 2 liter pot.

In other words, weight isn't everything! Function is more important.

For weight reduction, your best bet is to reduce the number of pots and pans. For me, one pot does it all. Since I eat out of the freezer bag I pack my dinner in, all I need to do is rinse the pot (if I've made tea) and my spoon, which really saves on washing dishes. (Can you tell that I hate washing dishes? )