I like walking and swimming... Probably the two least high intensity activities I could choose! They are what you make of them, though, so as long as I push myself I know I'm getting a good workout.
I walk/run on the treadmill. Granted the running only lasts for like a minute or two, but I do what I can. Sometimes I think I'm not doing much and should be doing more, but the next morning the number on the scale goes down.
Actually brito swimming can be one of the absolute BEST things to do for cardio, you use so many of your muscles you can get really sculpted if you do it enough.
When I first started working out I got on the eliptical and was winded in about 5 minutes, It was then I knew if I could just get a handle on using this machine I would be set! I can now do it for over an hour. Although it is my favorite because I am comfortable on it, I also dig the spinning bike, that thing kicks my butt!
I like tapes. I'm really liking Turbo Jam right now. I also like dancing. I'm starting to like the treadmill now since I have my ipod to keep me going!
I love the arc trainer. Whenever the trainers at my gym give a tour, they say the arc trainer is great for a lower-body workout -- it burns twice as many calories as walking on the treadmill. I liked that idea, so I gave it a try. I always feel myself getting a good workout on that machine.
I'm a big fan of the arc trainer too! It is probably my favorite way to get cardio on a machine. At first it was REALLY hard, but now it is easy for me to get my heart rate up and keep it there for my whole work out.
My favorite form of cardio not on a machine.. is kickboxing class! Also, before that I used to do the tae bo tapes. It's so fun and the time goes by really quickly.