I have tried all of the media players but none of these apps have done it at the same speed as WALTR. Depending on the video format, VLC drops the video and only plays the audio. MPlayer is terrible. PLEX - not so great either.
WALTR uploaded my movies to my iPad and I can play them back in the Videos App flawelessly (and also lossless, I might add - audio was also unaffected).
It did something interesting that HandBrake never did, which used about 75% of my CPU while it was copying over, so it must be doing some really heavy transcoding, but I do have to say that I'm happy with the result.
$15 is a small price to pay for this program, just for its speed alone. I wish it would allow you to add/modify thumbnails/categorization of the videos before uploading - my only suggestion to the developer (if he's even listening). I had to sync/transfer the videos from my iPad back into iTunes where it then allowed me to make those modifications.