Gimme your thoughts on these 3 mobos

Hi. I'm getting ready to build a system and would like some guru opinions on the following mobos because they look kinda close to me. My system will be budget to mid range for playing games with a few gigs of ram and say a 2.5ghz CPU. I'm not sure what SLI and non-SLI is all about either.

M2N-E http://www.newegg.com/Product/Product.aspx?Item=N82E16813131022

M2N-E SLI http://www.newegg.com/Product/Product.aspx?Item=N82E16813131096

M2N4-SLI http://www.newegg.com/Product/Product.aspx?Item=N82E16813131068

Here is a side-by-side chart from ASUS http://ca.asus.com/products_compare_show.aspx?array_model=1266,1181&l1=3

Here's all 3 in a side-by-side http://www.tigerdirect.ca/applications/category/compare.asp?CatId=2321

And I can't even find one of the mobos on the ASUS website M2N-E SLI

Thanks!