Which do you feel was the better system, and what made it better to you?

The 360 by lightyears. Just so many great games. Love that console.

Xbox was a nice system. I love Otogi and Gunvalkrie Jet Set Radio Future and such but Xbox 360 had a massive library and the only Xbox console with really good Japanese support. Even a couple of JRPG exclusives. It got most of the best 3rd party games. A lot of them run better than on PS3. Some at the time exclusive shmups.  It also to me in many ways felt like the successor to the DC. RROD is a major deal but thankfully the Slims don't and my slim is still fine after 8 years. My White Arcade one did RROD. 360 and PS3 were both great and IMO equally as good as one another in the end.

Original XBox had Knights of the Old Republic; it wins.

Xbox 360 hands down. Still have it and still play it 

I actually think the original Xbox is a bit underrated. It has arguably the best launch game of all time with Halo: Combat Evolved, a lot of great exclusives, and a bunch of PC ports unavailable on PS2, GCN, and Dreamcast. I played Morrowind and Half-Life 2 first on Xbox, for example.

That said, X360 has a better, more flexible gaming scene, with outstanding first-party titles in Halo, Gears, and Fable, a bunch of unlikely Japanese exclusives, and a robust XBLA.

As good as the original Xbox may have been, the X360 was way better.

From 2005 until 2008, X360 was the best cost-value console in the market. I have fond memories playing Fallout 3 and Gears of War on that machine.

Hardware-wise definitely the original Xbox lol.

Still, 360 had the better library and added the achievement system which is the reason why I wouldn't play an OG Xbox game ever again (other than terribly outdated graphics). Controller was better too.

Easily the 360 better controller way better software lineup, achievements, external HDD support, better online, the ability to install games etc. etc. On top of all that a decent junk of the original XBox games where playable on the 360.

It’s a lot like asking which is better, NES or SNES.

I had more fun with the original Xbox but 360 had better Variety. My whole life revolves around the original Xbox so I pick that one.