I don't know how many thousands of times we're going to have to answer this question but yours is just one of a very long list who just don't get it. These two companies make the best equipment available - there is no "better" so get over it and pick one that you like.
We dont need to check links, whoever is answering should already know these cameras.
Why do you think some say Canon is better and some say Nikon is? Who is wrong? Come on, it means both are great, otherwise one wouldn't even be out as it would hurt the reputation. These cameras are so similar it wont even matter which one you go with. Personally I prefer the T3i because D5100 has no ISO button and no AF motor built in.
Here's a DSLR Buying Guide - http://www.the-dslr-photographer.com/2009/11/which-dslr-to-buy/