What you're referring to is just personal achievements, not who's better. Osgood has more personal accomplishments then both of these guys but doesn't make him better then either. Luongo spent the majority of his career on a team that wasn't very good with no chance of competing for the cup. I don't see how that can be used against him.
You have a valid point. Sometimes goalies like Luongo and Lundqvist with all the talent in the world won't be able to win a Stanley Cup because they're not on a team capable of it (and I don't think either team really has a legitimate chance to win it unless they play lights out the entire playoff). But I think there is something to be said that given the high pressure situations Giguere has proven that he can handle it and that he is a safe bet if you're a team in the Stanley Cup Finals. Even Osgood as you said, isn't as talented as a good number of goaltenders in the NHL, but he is a proven success come playoff time. I don't like Osgood but I have to give credit where credit is due. He had a quality post season and no matter how he performs in the regular season he generally shows up for the playoffs.
Now, for me it comes down to a question as to --> Would you rather have a goaltender who has never experienced a Stanley Cup Final / hasn't had overwhelming playoff success or would you rather have a proven winner that has carried a team to the Cup Finals before? I'd rather have the latter AT THAT time of the year. Giguere right now is a safer bet for your team to win come playoff time. Luongo has had a great career, been one of the best goaltenders in the game for a long time, but hasn't had that same success in the post season. Same with Lundqvist. And lately, the same with Martin Brodeur who has been himself post 2005-2006 in the playoffs. Sure, a lot of it has to do with the team your on (especially in Henrik's and Luongo's case) but Giguere has been excellent in both the regular season and the playoffs throughout his career. He has been excellent and I do think Giguere has also been one of the best goaltenders over the last six, seven, eight years. Thats why in a poll like this I've got to give the edge to Giguere. He is one of the premiere goaltenders in the NHL he just had an off season.