*everybody* has opinions on this topic....
I feel that the pots you carry ought to be the ones that you *will* use, not the ones you , "well, may be I'll...", so generally a small kettle, a steep sided, deep pot with a good multi purpose lid that can double as fry pan/wok/plate is ample, and a sieve/steamer of some kind that fits inside the pot is awfully handy. Aluminium spreads heat well, but can very quickly get too hot, unless you can find a set with a sandwich base or let them get really manky on the *outside*.
S.steel/cast iron are great to cook with but they are heavy, if you can find thin s.steel pots with a sandwich steel/aluminium/steel or steel/copper/steel bottom you'll have brilliant pots, but not cheap
:?: Titanium? ouch on the pocket, but if light is your main consideration in buying a pot.....
That said we have a set of cast iron fry pan with an old fashioned pour edge and girdle, both with hanging chains, that are very hard to beat over open fires....there's a cauldron (ahem! a stew/ soup pot!) kicking about somewhere too. Great when there's a crowd or a settled camp but a real pain to clean and keep from rusting. Unlike aluminium though the pitting doesn't seem to matter so long as you scour them well before use.
Toddy, who found ransomes yesterday and is going to have them with lunch