What's your favourite gear ratio?

I'm running a very similar 42/18 due to crappy knees. I might change to 42/17 if I can get a bit more training in but, frankly, if it's a toss-up between being friendly to my knees and impressing the MAMILs, then my knees win every time.
For sure! Those MAMILs will be off their bikes or having join replacements while we're still peddling :)