I'm extremely sorry to hear that you lost all of your data...it's happened to me a few times in the past, so I feel your pain on how bad it sucks.
My solution, which can be a bit time consuming and annoying to do all the time, is to back up all of the save data I really care about to a 16gb USB flash drive when I finish playing whatever game I'm working on. It honestly only takes me a minute or two to go to the storage menu and do it for whatever I just finished playing, since all of my other saves are already backed up...on arcade games with no separate save files I'll just copy the game over or just play it from my flash drive. I personally use a Corsair Extreme XMS ultra high speed 16gb USB 2.0 drive, I picked it up from Newegg.com about six months ago as one of their daily deals, it was regularly $69, on sale for $39 plus it had a $20 mail in rebate on top of that. I keep it in one of the front USB ports on my 250gb slim 360 and periodically back everything on it up to a directory I made on the desktop on my laptop. I've had things go completely corrupted since I started using it, Microsoft had to send me a new 250gb drive, which actually worked out in my favor as they told me I could discard the corrupted one...it works perfectly fine again since I did a format on it. The other perk was that I could still play my games since my saves were all on my flash drive...at the time I had been playing CoD black ops & Battlefield Bad Company 2 a lot and just re-downloaded the two Blackops map packs & title updates as well as all of the BFBC2 maps and updates directly to the USB stick, backed it up on my laptop to be safe, recovered my gamertag to USB and went back to playing as if nothing had happened for the ten days it took for my new 250gb to arrive from Microsoft. I highly recommend my method, as it safeguards your data completely -'even if the flash drive somehow ended up corrupted I could simply format it again and copy all of my data back onto it from my laptop. I don't know if my method would be practical for you, or even if you'd want to bother with it, but I can honestly say it's saved me a ton of time and frustration when my console has screwed up on me.
Again, I'm truly sorry to hear you lost everything, and I hope that my method of backing up data might be useful to you.
Big thanks to jtr1gg3r for the sexy new sig!
70,000GS 26 Oct 2010- RB3 "Hometown Threwdown"