Most only go up to 192k + 720p as far as I’ve seen
Which is the best free one?
You mean to download?
I use jDownloader, which works fine.
Tru 
Thanks!
Intending to rip da SHISHKEBAB vids before they’re inevitably removed
Oh, if you don’t already have it keep an eye out on their forums for an ad-free version
Their standard download has ads inside the program, but it so happened that there was a bug with this during the week I downloaded the program 4-5 years ago, upon which they momentarily offered an ad-free version in their forums. A friend installed the program as well about a year ago, and we then discovered this link to the ad-free version in fact still worked. He found it by himself so it is somewhere there (or was somewhere there last year), but if you can’t find it I might have it in my e-mail archive.
Otherwise the ad version is probably fine too, just more annoying.