I prefer to use a variable name that describes the type of the object in short.
So if my "this" object is actually an AwesomeTableWidget instance, I might do:
var table = this;
I like the bit of extra documentation it provides... Or maybe this is just a remnant of all the C code I've written over the years, where it's common to have an object pointer as the first argument to a function and it's usually named like this.