I was playing my PS2 and while saving, I was warned that my data had become corrupt. I was wondering if I should take my files and move them onto another memory card or leave them on their current card. (I deleted the corrupt data.) Please help. I don't know what to do and don't want to lose any data.

Memory cards are cheap so buying a different one won't hurt your wallet.

Though, it could have been a freak thing. Has this happened before? If so, buy a different memory card. Otherwise don't panic.

It seems to be a common problem in that brand of memory cards (MAX Memory). Can I copy the save data to another memory card (Official Sony PS2 8MB) without harming the memory card. I've put at least 300 hours of my life on it.

What game are you playing ? I had the same problem while playing Soul Calibur 3 till i found out, that the PAL version had a save file bug. It corrupted every save that was created BEFORE itself, but only if this file was altered. A strange and rather destructive bug.
But a good option would be to move your files while they arent all coruptted and format your card a couple of times or e
ven better, get a new sony card, Better safe than sorry

I started a new game in Kingdom Hearts II. I'm going to move them over right now to a Sony MC. It was working fine 2 hours ago and then I tried to save and it told me the save had failed because the data was corrupt.

Yes, i also had a MAX Memory card.
That card died right after i used it. They are absolute rubbish. Get yourself a bunch of original sony cards off of ebay or amazon. They are dirt cheap and even if they are smaller in capacity, with that price you can go the "quantity over capacity" route

Yeah, I just copied my data to my Sony. It seems like I've lost some System Data for a few games. Any idea on how I could get it back? (not fix it but find completely new System Data)