Anyway, you just can't beat the dramatic irony at the end of Jurassic Bark and Time Keeps on Slippin'.
That was just sad, not ironic.
OMG, the end of "Time Keeps on Slipping" was a little ironic, in a way. Definitely unexpected... but it was just... whoa.
"Jurassic Bark" did have dramatic irony, because we the audience know that Fry isn't going to come back, but the characters in the past do not. Also, Fry didn't revive Seymour because he thought the dog had forgotten him, but we know he didn't.
The ending of "Time..." was more situational irony, when the opposite of what is expected happens. We expect Leela to fly the ship, but because she feels bad for Fry, she lets him do it. That doesn't seem like it matters much, but remember, if Leela had flown the ship, she would have seen Fry's message and fallen in love with him. But instead, only Fry sees it before it's destroyed.
It's interesting that the reason Leela didn't see the message is that she liked Fry enough to feel bad for him; because she liked him, she missed the event that would have made her love him. And she would've had to have flown the ship if Fry hadn't learned how to do it, but in that case he would not have been able to make the message. Very complex, though not wholly ironic. Is there a term for any of that (besides "bummer" )?