What's your favourite gear ratio?

is there an "ideal" RPM? i am current 46/18 which (when adjusted for tire size and crank length) is 68.4GI, giving 18.3mph at 90RPM. Am going to 44/18 which gives 65.4GI and 17.5mph at 90RPM (using sheldon). basically, because i like to spin.

I think 87-90rpm is idea for sustained high speed riding. I've tried slower, and i've tried faster, but it seems to work for me. I believe, however, that the hour record, which is probably the best test of sustained riding, is usually run at 102rpm ? Or i may have dreamt that !