You really should do your own research.

Anyways, I'd always chose VB.Net over PHP because it enables me to use C#(Which I personally find to be the best high level language to date), but it also has all the advantages of the .Net framework.

Truth be told, I'm not sure you can get an objective answer here, and the language itself isn't really that important. If you need to learn both from scratch, just chose one and go with it!

My 2c