Has anyone won a game when you did not capture Orion and get the goodies?

Speaking for MOO 1, which is primarily what i play: I take it if it's convenient, but it's low priority. The multiple free techs are a great hail mary for clawing back into it against a runaway AI! But generally I find I win or lose games long before my fleet is advanced enough to waste the guardian without making a specific anti-guardian fleet. (bajillions of NPG fighters, that sort of thing)

I primarily play on average size/impossible, and that probably plays a role in the decision. The guardian is wimpier on lesser difficulties, and larger galaxies often lead to longer games where higher tech levels are achieved and fleets are larger. When you can end an average size game with Megabolt cannons, who needs death rays?

Many times. On higher difficulties The Guardian is nasty and by that time i probably win the game via diplomacy.

Me too, seldom do I need to beat the Guardian to win, rarely do I bother to. MoO1 or MoO2 does not matter and in MoO3 I never got that far.

I had to go out of my way to grab Orion so far.. anytime I was even thinking of heading that way I was already just a step away from winning.

In MoO1 I never bother with Orion. It simply feels more trouble than it's worth.

In MoO2 on the other hand, it is possible to beat the Guardian with relatively low tech, which also means that the benefits are more substantal at that level, so I try to conquer it as soon as possible.

In MOO2 (which is about all that I play of the series), I grab it just to keep the PC's from getting it.