I've met two girls over the internet. I've never used a dating site, and never intended to meet someone via the internet, but I have:
The first I met via my blog (she read my blog and emailed me). We chatted by email, then IM and then alot on the phone (some times all night, 8 hour phone calls). We eventually arranged to meet so I went to OK where she lives, she's a university student there. We had 3 great days together, even stayed at the same on campus hotel (though I wouldn't really recommend a girl do that). We kept to separate bedrooms. She is a very nice person and we got along very well, but we decided that neither of us was in a position to move so we'd better stop it sooner rather than later. She's still a good friend, but we're leaving it at friends.
The second girl I met was on IRC. We just started chatting, then talking on the phone ALOT. I've visited her quite a few times and she's been here several times too. It's easier for me to travel, so I go there more. We're still dating and at this point are committed to eachother and have a full blown relationship. Plans are to live at her place in the summers and here in the winters. We both have kids and school and stuff so it's taking a bit of time to make things happen, but at this point that's the direction we're going.
So at least for me, dating people I've met on the internet has been nothing but good experiences.