Preference.
By nature, DSL has better latency. It is, however, generally slower, somewhat.
Cable is shared on a per-neighborhood set up, and can become over-saturated in some cases, such as in emads.
Here, we can get either Verizon DSL of 3/768, or RR of 5/384. We've got the 5/384 as our local verizon CO is full of a bunch of morons, which have screwed us over on several ocasions, which is why we switched to cable. Both are the same price, one has faster downloads, one has faster uploads.
As far as reliability is concerned, I had a better experience with DSL. It was always working, always with 90% of the rated speed, great pings, however with the screwing over by our CO, we got rid of it. RR has had a few times it didn't work, pings aren't quite as constant, and ironically RR had a huge crash in my state, disabling many locations. That, however, was [speculation:] caused by their recent download speed increase to 5mbps, stressing the network and it's components past what they've had to endure ever before, and frying something. However, over-all, not a bad experience.
It depends on your location. If you live in a highly populated area, DSL would more likely be your way to go, as there would be more connection bridges, and less worry about neighborhood-overload, if you will, however the further you get from the CO, the worse you speeds get. Cable is a little more resilient to such things such as distance, and would more than likely be the choice in not-quite so populated areas.
Of course, that is just a general rule from my experiences. It varies greatly from location to location.
Could we get the specs on what packeges both your Cable and DSL choices provide?