Back in about 2004/2005, the Most Patient Husband and I realised we would both like to go on bike holidays together, but our performance on bikes was, how shall I put it: slightly dissimilar. Slightly as in that famous race between the hare and the hedgehog, only without the hedgehog trick. (I was the hedgehog, by the way. Still am.) So the obvious solution was trying out a tandem, and we started right away to look for one with good luggage capacity to get holiday equipment onto the bike without having to add a trailer (which is the usual solution for tandem vacations).
We stumbled across a slightly unusual bike that way - the Hase Pino. Which was a semi-recumbent, and we'd never had contact with 'bents before, so it was all very weird and new. On this, you have the usual luggage rack that will fit three bags (two panniers and a topcase), plus an optional lowrider underneath that will fit another two large and two small panniers. Which sets you back a bit compared to two single bikes, but not so much.
So we went to our local bike dealer for special bikes, ZoxBikes - and he did have one of the tandems... so off we were for a test ride. The first metres were very weird, and the first corners doubly so, as the stoker (the one not handling the steering stuff) sits on top of the front wheel. Which means the captain (the one who does handle the steering stuff) has to guess where the wheel is, and the stoker has the feeling of going straight into a wall or the abyss that you can get when you sit in a bus right in front.
A little test round an a slightly larger test round later, we went home... and we got our tandem in October 2005.
It's a relatively pricey bike (you pay extra for exotics), it does have quite a few flaws (there are some technical details that are, well... questionable), but we haven't regretted our decision for a single second. We've gone on tours long and short, we've hauled all kinds of stuff with it, we've spent wonderful vacations in Spain and (most often) in England with this thing. We also use it as our main daily means of transport when we go somewhere together, year round - on spike tires in winter for safe riding.
So. That's the tandem story - or at least the first part of it. If you have questions, ask away in the comments, and I'll write more!