I was thinking about this yesterday, and I'm thinking that it would be my tandem, or my folder. I'm a utility cyclist as well as a recreational one, and the tandem does it all. It's got front and rear racks fitted, and it'll haul my trailer, and has a basket, so it's a great load lugger. It's actually quite a decent ride solo, not noticeable heavier on the road than my Raleigh 3 speed, for instance. Low maintenance, with it's SA 3 speed gears, comfortable to ride for hours, I can ride it in any clothes or shoes, wide tyres and fenders are good for all weathers, and, of course, I can carry a "passenger". Wonderful. Of course, it is rather big, and unsuitable for carry my briefcase, or taking on the train, unlike my wonderful Raleigh 20. Hard choice!
This bike has a front rack, a change of saddles, a frame bag, and water bottles fitted since this pic was taken.