On top of that, linguistic preferences are rarely formed objectively. Taking PHP and C# as examples, I don't prefer PHP necessarily because it is "better" than C#, though I might at times claim it is. I likely prefer PHP because it suits my current coding preferences better: I can code efficient PHP more efficiently than I can code efficient C#.
As a general trend, I might also say that PHP sites feel faster than C# sites. But, I don't have concrete numbers to back that up. Nor do I have a firm understanding of the complexities of each site so as to make an accurate comparison. Perhaps simpler sites are just built using PHP, and more complex ones with C#.
If you're looking to get started with a new language, just pick one that's highly popular. Popularity generally ensures a good degree of community support (like this forum). But, be quick to respond to changes -- had you posed the question 10 years ago, I'd unequivocally recommended Perl. But, if you're still writing Perl today, you'd be wise to abandon it for web development purposes.