His serve is the last thing i would say i like about Tbird's game tbh
This unorthodox uber high toss is not what i would call pretty and it's quite dangerous for himself. Of course he's mastered it enough to have no major issues with it, but you wouldn't teach a kid tossing this high for sure.
The rest of the motion is just standard imo, nothing impressive nor pretty overall.
Fed's motion's been perhaps the most fluent and flawless of them all, but i believe Fed's serve has been way too low in speed lately, he's slicing/spinning/kicking the ball way too much and it doesn't have that much efficiency of late.
Andy Roddick's serve motion has always been my favorite overall. Perfect toss, short opening of the racquet, perfect rotation of the upper part of the body, my fav grip (one of the things i dislike in Tbird, Soder and Tsonga), explosive arm movement - all perfect.
Compared to Roddick's explosion of a serve, Tbird's slow-mo is far from being so great in my opinion.
A matter of taste ofc
His was famous for being effective but ugly.