- The clock stopped ticking forever ago. (Idiom, I think?)
- I've been waiting for centuries! (Hyperbole)
- Time's gone by as slow as molasses. (Simile)
- At long last (Idiom after waiting is over)
- I've been watching the clock for a long time. (Idiom)
- I must have had a lot of time to kill. (Idiom)
