I've never played a single Mega Man game, barely even touched one. I'd like to give the series a try, but a certainly don't want to play all of these games since so many seem similar. What are the essential Mega Man games for someone who wants to get to know what the series is about. I'm not just talking 1-10, but X and whatever else is out there in the side-scrolling platformer/shooter mold. Feel free to recommend as many games as you feel are essential, and if there's a preferred order. Can I just play Mega Man 2 and call it a day?
UPDATE: This has been really helpful. Seems like 2, 3, and X are getting the most love, followed by 9. A couple Legends mentions too, which has me pretty intrigued. I'm still interested in suggestions, but wanted to summarize sentiments so far.
UPDATE 2: OK, that settles it. I'll go to some used game stores next week to try and score some copies of Mega Man 2 and 3, and I'll check out the Legends situation while I'm there. I don't have a SNES so I'll download Mega Man X on Virtual Console after I've played 2 and 3. Seems like that should cover it unless I'm really driven to play more after finishing these. Thanks to everyone who offered advice.