DAPlayer is a free media player with a reasonable feature list.
The program doesn't just play a few standard file formats, for instance. It covers just about every video file type there is, including many 1080i/1080p HD formats: M2TS, AVCHD, TP, MPEG-TS, EVO, MKV, AVC, MOD.
And DAPlayer isn't just another DVD player. It's a region free DVD player, so you won't be hassled with annoying messages about changing your DVD drive from one region to another.
Better still, there's some support for playing Blu-ray discs, both commercial and home-made.
And the program is optimised for performance, with the authors claiming a mere "10% CPU cost on i5 CPU when playing 1080P AVCHD video".
This didn't always work for us - Blu-ray playback was particularly unreliable - but if you've had problems with other media players then DAPlayer may be worth a try.