I liked
Event Horizon just fine...up until the final act where it all falls apart. That plus Sam Neil's cringe-worthy attempt at a scream just killed it for me. And yes,
Sunshine had pretty much the same problem (sans hammy screaming.)
Oh, and it's probably a bit obvious but it only just occurred to me that the mysterious figure could be what the space jockey looks like out of it's suit. It'd certainly explain why the chair is empty and what that big human looking face is about.