When I was cycling "seriously" it was bananas, mainly because I couldn't afford anything more elaborate. The rule was subtract 1 from the number of hours that the ride would be, then take that many. Coming back to casual riding in my thirties, a bit of chocolate chip brioche wrapped in foil had a touch of continental flair to it, mostly due to being French, and it would still be edible even if it got a bit squashed. Fortunately, M&S was the best brioche and also the closest supermarket, followed by Sainsbury's some way behind in both measures. Malt loaf's a bit sticky for my liking although it would otherwise be perfect... never tried KMC but I imagine it would produce a big sugar spike, followed by a bigger trough.
Running's quite boring from a food point of view because only my longest runs need any sort of "nutrition", and even then only if there's pace in them. Jogging 24 miles on l'eau claire is fine, but it's still bananas beforehand, but if we're straying close to marathon pace for any length of time then those messy gel things come out. If I've travelled to run then wholemeal bagels with chocolate spread are a good thing to shovel in on the drive home, or Tesco do a sort of chocolate-filled 'crepe', which doesn't squash and can be eaten from the wrapper easily with dirrty hands. (One time I swapped the bagel for a seed-topped roll and cracked a tooth, eventually leading to an emergency extraction and missing the National Road Relays, so be careful...).
My van's due to be delivered on Thursday this week, so it'll be fun to see if the routine of bagels changes to anything more elaborate, or if I just delay cutting and spreading them until a later point in the day.