I own Gold, Fire Red, Emerald (now original cart, but had 2 bootlegs before), Pearl (also had 1 bootleg before), Platinum, Heart Gold and Black. And so far...
I've never got my save corrupt, but deleted in Gold - but it was well, pretty old, and the poor battery just ran out. The only downright of it all is the fact that my game keeps glitching randomly, but I guess, it's more of my fault, because I love to trigger all kinds of glitches on my games.
With two fake Emeralds, save file on them was always corrupted, even when I just started a new one. And of course, it got erased right after the pokemon League. Also, I can mention I had one bootleg Sapphire which didn't even save and was well, all weird.
Pearl has a funny story though. It taught me that DS games are really sturdy. First thing, I remember my DS froze while saving the game - and then it just restored the previous one. So except that, all is running okay on it. A little quirk though, I remember my game kept freezing when the playtime on the save was exactly 300:00 hours - though, when I saved at 300:01, the freezing was gone. After that I started playing around with Action Replay and whatnot (all berries and tms cheat + activating the events like darkrai) and my game is still perfectly fine, together with it's save (okay, except the fact that my DS doesn't always read it, but from what I recall it does it with other games too, so it's rather my console's fault). I also mentioned I had a pearl bootleg - which was a whole different story. The save file maybe wasn't corrupted, at least it wasn't saying it, but the game kept freezing all the time, trying to use fly also froze the game, and eventually, the save just deleted itself randomly.
My other games, though, are perfectly fine. I don't think I need to worry about anything except the Gold version. Not to mention this one is old and I got it from a friend who doesn't treat his games well.
My opinion on this is, I think that save file can't just get corrupted surprisingly over nothing. Unless you really do weird things with your cart. (my Pearl survived a lot and it works perfectly, so I can only imagine what one would have to do to corrupt their file.)