Casual. I love the shades of red in different areas, but most of all the background color is perfect for the eyes. Most people would think straight on white background would be good, but the shade needs to be slightly darker, hence why I love it.
So in other words, Casual is good for TNE and your eyes.
Let me tell you why @mattavelle1. Xenfoogle is "a google-inspired skin" (their own words), which I know you don't want. Casual, on the other hand, is the most hardcore of the skins. Like a guy so manly he's not afraid to wear pink dress shirts. It also just has the best color, and fits the most with the TNE colors of old.
So what you do is you go here down to the bottom left, where you said it says "forum software by XenForo". Right above that, you will see that it says "XenFoogle" check the picture I took.
Just click on it, and it will give you four options to select from. Just click on casual and join the casual master race.
Casual all the way. I only have a choice of 3 styles but after trying the other two I want to punch my eyes out with a fork. Tooooo bright. Casual is nice and has a good, warm quality to it unlike the frozen, strobe-light tundra of the others.