For pr0n; Sasami2k
For movies; Zoom Player
I think other players have strengths and weakness's and doubt there is a definitive player. I have about 6 players installed for different purposes. It's not like they take up a lot of space
Some are better for correcting aspect ratios, multiple audio tracks, subtitles, etc. Zoom player is just highly configurable, and supports spdif output. Sasami's biggest weakness is the lack of spdif output.