Except for mkv files with subtitles, there is something that Haali+wmp can't play. Vlc can, but I prefer mpc-hc.
To be honest, that is true. I always forget about subtitles because I every rarely use them, if ever. 99.9% of the movies I have have native English audio tracks.
Still, any video out there will play in 7 with just Haalis added.
Like you, I prefer MPC-HC as well.