Two endings, for the Jap release and the US release.
JAP: The city scene, where he looks up into the sky.
US: Where he ends up as her bodyguard, and looks down on her from the balcony.
So no, you did not imagine anything

The OVA (3 episodes) version and the Movie version had different ending sequences (along with music).
Music
OVA: White Reflection
Movie: Last Impression
Duo
OVA: Duo is standing on top of junk heap, Hilde runs up and gives him a clipboard or something
Movie: Duo is making a deal with some guy, runs off happily to have lunch with Hilde, chokes on his food
Trowa
OVA: Trowa is seen going back to the circus, being welcomed by Catherine
Movie: A circus performance with Catherine jumping off a trapeze and landing on Trowa's arms while Trowa is standing on a tight rope
Quatre
OVA: Quatre is celebrating in a ship with the Maganac Corps
Movie: Quatre is seen working on a construction project of some sort with the Maganac Corps
Wufei
OVA: Wufei is on a ship with Sally Po
Movie: Wufei is working as a Preventer with Sally Po, riding on a jeep and blowing stuff up
Zechs
OVA: Does not appear in OVA's ending sequence
Movie: Zechs is playing chess with Noin and Noin appears to be winning
Heero
OVA: He's standing on a balcony, watching over Relena who is giving a speech. We see a close-up of Relena and when they give us a shot of the balcony, Heero is gone. Then we see Heero walking with outer space as a background
Movie: Relena is meeting with delegates. She looks up and we see Heero in the middle of a crowd in a space colony. He looks up too and says, "Mission Complete" before walking away completely.

That was at the End of the series. As for Endless Waltz there are three alternate endings, the manga, OVA and the film version.
The OVA and film versions are strikingly similar. Except for Heero and Relena I believe. In the film Heero is on the streets in a colony with the whole mission complete thing. In the OVA Relena is inside giving a speech and Heero is looking after her. In the manga (which is one I haven't read personally) the pilots go to Mars. But I'm not sure about the manga ending, but that's what I've heard.
"What? No. We Can't Stop Here. This is bat country."-Fear and Loathing in Las Vegas

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I don't think so now, because I rented the DVD a long while ago
and there was no alternation or anything. maybe i need to check
again ><

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there's an extra?!?! and Relena read a letter from Heero ..
I gotta check this out ><

]Marie maya and Une are still at the Treizes grave.
2]Duo tries to get this metal thing of this guy,then goes to have lunch with Hilde,and he chokes on something he drinks.Its very funny!!
3]Quatre is helping to rebuild the colony that marie maya was in charge of.The maginec corp are with him
4]Trowa and cathrine are performing at the circus with the ring master.
5]Wufei [whos still a preventer]and sally are testing some kind of explosive in a dessert somewhere.
6]Zechs and Noin are in space playing chess
7]Relena is at a big ceremony with some political leaders,then smiles and looks up into the sky[proberly thinking of heero]
8]And finally.Heero is in a big city stops and looks up at the sky as the same time as relena[proberly thinking of her]Then he says his famous 'Mission complete'[but only in the english dub,dont know if that matters or not to you]The he smiles and disapears into the crowd.And the movie ends.
whoa wait a second, the only thing I saw was the 1st one and the scene that the OP mentioned. I remember, Duo, Trowa and Quatre blew up their gundams in some park and Wufei doing the same elsewhere. Also, Duo talking to Hilde, but not the going to lunch part. That sucks guess, Ima look for that ending..

the end of the series was different, Relena read the letter Heero wrote or something.
"What? No. We Can't Stop Here. This is bat country."-Fear and Loathing in Las Vegas

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I beleve thier is an alternate ending asa dvd extra somewhere.

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