This is simply a tweak of confuciou@userstyles's Bigger Youtube HD and blue2107@userstyles's My Youtube Resizer for 1280 x 720 resolution, so all credit should go to them. I wanted a bigger video for YouTube however hated not having the video information along side of the video. I changed around a few of the numbers in order to make the styles look better (IMO) for resolutions ranging from 1152×864 (kinda stretching it) to 1440×900 (slightly larger than normal YouTube).
I use a widescreen monitor at 1366×768 so your mileage will vary. It is not, I repeat, NOT 100% perfect. For the life of me I cannot get the videos within profile pages to work correctly. I honestly never view videos through these pages, however if you find it extremely irritating I will try my best to solve the issue (and learn CSS).
Feel free to modify this as you see fit, as well as recommend newer features/updates to me. You can get in contact with me at: oddistic@hotmail.com

Enjoy!