My kid wants to play Pokemon - Where does he start?

[GrimReality]

Thanks a ton, guys!
We've got a DS that plays GBA games, so it doesn't matter either way. He's also not picky about graphics. He's played through the Mario Galaxy games, Loved Metroid Zero Mission, and is now playing Super Mario World.
He can get by with just one game, right? It seems like they always seem to be released in pairs. Why is that?

[John]

Thanks a ton, guys!
We've got a DS that plays GBA games, so it doesn't matter either way. He's also not picky about graphics. He's played through the Mario Galaxy games, Loved Metroid Zero Mission, and is now playing Super Mario World.
He can get by with just one game, right? It seems like they always seem to be released in pairs. Why is that?

Cash dollars!  Most of the games are pretty close facsimiles - there are minute differences between the two versions, usually about 30 Pokemon or so that are exclusive to one version or the other.  They have a tendency to release a "combined" version about a year later.  Pearl and Diamond became Platinum.  If his friends at school are big into it, it's not a huge deal, since he can trade with them.

[Starmongoose]

To get yo money, of course.

There are a couple of Pokemon that are exclusive to one of the pairs. That's the only major difference.