I also have one bicycle dedicated (well not completely) to a trainer and I also have a set of rollers. In the winter I spend a lot of time on those two.

Having done all three, swim, bike run, essentially all of my life, it is not only that I enjoy swimming more (I like being able to tun my brain off, I cannot do that cycling or even running) but the constant resistance from the water adds to it's benefits, IMO, they are significantly better than running or cycling, not to dismiss either of those as a form of exercise but what I am saying is that if I could only do one, then the one would be swimming.

Even before I could walk, and certainly before I could ride, (broken femur, non union) I was able to get back in the pool. My atrophied leg began building muscle quickly and I am positive got me back walking and riding sooner than had I waited until I could ride to begin to work out again. The swimming got me going probably two months sooner and my doctors were amazed at how quickly I recovered given the damage to my leg.

I do want a home gym but I belong to the Y, they have a climbing wall and some other fun stuff, it does not cost much and I have no aversion to automobiles, trains and planes. If it takes a car to get me there, no problem. But, I do hope to someday be able to live where I can ride to the Y etc.

LC