Here's a contrived example to demonstrate the value of sigils:

    /* in version x of SFL (Sigil-Free Language) */

    school = get_school("Saint Fred's School For Girls");
    class = get_class(school, "Agricultural Studies", 12);
    yield = get_agricultural_yield(class, "Turnips", 2011);
    printf("The Year 12 Ag Studies class produced %d turnips in 2011", yield);

Now we try upgrading to version x+1 of SFL, which adds object-orientation and concurrency (it was a BIG upgrade!). Now three of the lines in that four-line program contain errors, because "class" and "yield" are no longer valid variable names, having been turned into keywords.

In a language with sigils, that's no problem. It also makes it easier (therefore faster) for syntax highlighting to spot where variables are used, without needing a full dictionary and an exact version number - that makes a difference for me as an Emacs user especially.

I like it as well, it makes it very clear what is a variable and what is some other sort of identifier.

etfb is on the right path, but for me it just feels right. I guess that's just a personal preference, but the dollar sign is a visual indicator that a particular string is a variable, and not a function call.

For me, it makes a big difference in languages like ruby where you could either be calling a method, a monkey-patched method_missing callable, or a property in some scope.