I queued over 5 hours for Dragster when I was at Cedar Point (opening year or possibly the year after, can't quite remember...) and it was **** worth it- I knew I wouldn't be going back to Cedar Point for a long time and the ride was obviously one of a kind and a bit of a phenomenon back then.
Strangely I queued only about 2 hours for Kingda Ka the year that opened.... though I was fortunate to have visited the park on a very quiet day.
When I was at Alton Towers a several years ago, I got talking to some people in the queue who were behind us as we queued for Air who informed us that some friends of theirs had queued 10 hours (didn't get to even see any other rides, they went to the queue when they arrived at 10am ish and were there till 10pm) for Air a few months earlier (it was the year Air opened)..... I obviously don't know if they or their friends had been exaggerating, but I do believe the bit about it being the whole time they were at the park..... **** that for a laugh, how gutted would you be?