I voted for OG Xbox,and let me explain why right after a brief look at my console history...
I own and a (modded) OG Xbox and a (modded) X360.
I also own a (modded) Wii (actually 2 of them) and a (modded) Switch.
In addition, I own 3 PS2s, 2 PS3s, 5 PSPs, 2 Vitas, 3 3DSs as well as android emulation machines.
OG Xbox is simply amazing.
* Its graphics are usually better than PS2 and GC.
* It supports component cable and 720p.
*It has a vast library of third party games.
* I love the Xbox controllers and support for 4 of them.
* I love the ethernet port and simplicity of connection.
* I love the XMBC support.
* I love the HDD support (with mod, you can add 500+ GB drives).
* I love the emulation support (I love thousands of retro games installed).
* It's incredibly easy to find old roms and upload to the Xbox and have a huge library of nostalgic games on demand.
In short OG Xbox is probably my BEST ps2 generation console. WiiU, on the other hand, is a premature version of Switch, which I really enjoy. Don't get me wrong, Nintendo's heart was in the right place with WiiU, but they just couldn't set the formula right with it. So Switch is actually a mature and perfected WiiU.