FIOS is fantastic if you can get it, but most of us can't.

I can only speak to my limited experiences- I have had Verizon DSL and cable modem service from 2 different providers. DSL was always rock solid- it never went out on me. My first forray with cable was fast, but flaky- it suffered from frequent disconnects.

I've been very happy with my current cable provider. I get 5Mbps download speeds and it's very reliable. The only problem is upstream, which is just 512kbps. Even with that though, I've hosted (small) TeamSpeak and game servers over it with no problems.