The best would be the ability to be like a human genie, without being in a lamp or having any limitations to how many times or what you can wish for.
If you did that, you could simply wish for anything you want. You could have everything you want, and eliminate everything you don't want simply with the power of a thought. You could also wish for ever power, making you absolutely invincible and unstoppable.
For me, the age old "best super power" question depends on a few factors; however, the first question I ask is probably the most important factor.
1. What is the extent of my power?
The thread starter gave us absolutely no limit to our power, so I don't need to ask any other questions. The answer is already comically easy.
Reality Warping.
I don't see why anyone would go with anything else under these conditions. You can just give yourself the other powers if you want to be Flash/Superman/JeanGrey/Spiderman/etc for a while. And don't give me that "it's too much power and would be boring" BS. It rocks and you know it.