Obviously a lot of people on here have TVs where playing back DTS is a problem, but just wanted to know what hardware most people opt for to get around this? By the way, I don't have an A/V receiver or surround sound, just playback via in built stereo speakers at the moment :(
Nowadays, I would go with a blu-ray player instead of a media player. Most new blu-ray players already support mkv/dts through usb playback (a format Blu-ray owners have been requesting for years). The LG you listed is good for a cheap bd player, although some users have complained about poor dvd-upscale and mediocre "smart" (apps) feature, otherwise it should be a good player.
Blu-ray playback quality is usually the same nowadays with most Blu-ray players, and they've come down in price a lot.
Personally, I like Sony's BD players. DVD up-scaling is really good, and will play almost anything from USB (except flv, iso - which no bd-player to date plays these yet, but simply converting the iso to dvd files or mp4,mkv will work.)
It should come down in price, since Sony stop selling their older BD players on their site every time they release a newer model. Panasonic would be another good choice.
Or if not, the LG should be highly capable of playing full 1080p movies from USB.
The step-up model LG BD670 is better than the BD660, but it?s almost the same price as the Sony BDP-S580, which is a better Blu-ray player. For Blu-ray and USB play back, you really can?t go wrong with either of the 3 players listed above.