I am a great fan of browser based stuff so I don't have to install a *special* app for doing the same task.
For example, the original Youtube app bundled with iOS (before iOS6) was a waste and it doesn't even offer HD content. On the other hand Safari lets you choose HD option.
Recently I see many people started using Jasmine. I was told that this is from Jason Morrissey (yeah, the guy behind Alien Blue) so thought of giving it a try.
I must say, the first look itself is pretty impressive. The interface is simple & elegant. The focus is on "search" functionality. I felt that somehow it is rather fast compared to browser based youtube, and also the playback is smooth.
Now the bad part, is you'll lose the options in Youtube. i.e. the browser based search queries, , long, recent, etc. Also it doesn't let you sort by date, popularity etc. So end up going back to browser based :)
However if there is an app which is simple, elegant & easy for youtube, then Jasmine will be at the top. You can try it @ iTunes.