I've got a Martin Backpacker that I take every where that has the 20 year old OEM strings on it.
The darn thing sounds like a Mandolin when I play it and I don't want to mess up the magic with a fresh set of strings.
When a string finally breaks... I don't know how I'm gonna feel about that instrument.
One of my favorite sets of strings lately has been a set of flat wounds I make up by buying a set of Fender light flat wounds and a single "10".
The flat wounds are something like 13-52 but I end up with a 10-47 set, or something like that... I forget the details.
Another favorite set is the Rickenbacker semi flattened 10-42s... those things feel sort of slinky and sort of flat wound. Hard to find... easy to play.
Each of my guitars has different strings and set ups so that they each have something interesting to offer when you grab them.
I usually buy 10 packs of strings when it's time to re supply so I have a big plastic box of all kinda my favorite strings.
Fun stuff.
best regards,
mike