Which sub-$250 streamer to buy for media files and Netflix/Hulu+-type content?

The Roku and WDTV are both good choices. They will both stream netflix and hulu. Streaming large rips without skipping frames will depend on your network. If you are trying to stream wirelessly, then a 20GB file will probably skip. Wired should be fine. If you don't have a network drop at your tv location, then play it from a usb flash drive or external hard drive before you try to go wireless or powerline.

I have a WDTV hub and it plays every format I throw at it. I would recommend the hub if you want to spend the money for it. It has a built in hard drive so you can transfer your rips to it before you watch.

They will both work with either your receiver or sound bar.

local content playback. the roku and wdtv are ment for online streaming mostly, while the dune and pch are focus on local content. So they support every audio codec every video format,

With Roku you will have to use Plex or some type of Media Server to transcode the video file. WDTV can play video files, and has online streaming options. However, I did noticed that the WDTV has issue playing some MKV and MP4 files. So, if you go with the WDTV option, I would suggest ripping movies to M2TS format.

Wireless will not work to stream high bitrate video.

I like having a two box deal. I use a Dune Smart Series D1 and PCH-A210 to stream my rip movies. I use a PS3 or Xbox to access OLDFlix and other online streaming apps. The other option that I like about Dune and PCH is that you can have a nice looking jukebox. You can do the same with WDTV, but it is painfully slow, and a PIA to edit.

The Dune D1 is about $350 now. The PCH-A210 has been discontinued, but it plays the same file formats as the Dune does. The Dune Smart Series will probably be discontinued as well...they might have been already. Both of those play BD ISO's with menus. The new media players do not play BD ISO's with full menus. The Dune has a fast UI, and the Zappiti jukebox is pretty simple and easy to use.

The PCH-A210 uses YAMJ as a jukebox, which is HTML based. You can use the Eversion skin which is Flash based. I use YAMJ/Eversion, and I have it set up to where it automatically goes to the jukebox rather then the UI.

The issues that I noticed with MKV and MP4 files where the following:
1) Stuttering and lag.
2) Fast Forward would cause the stuttering and lag as well.
3) Chapter skip would do the same.
4) Audio drops, unless you change it to a secondary AC3 track.
5) WDTV doesn't support DTS-MA only True-HD.

99% of my movies are ripped as Main Movie Folder structure with M2TS file, which both my PCH-A210 and Dune D1 player perfectly without issue. That's what I noticed with the WDTV as well, it played all of my M2TS files without any issues. I've got about 4 BD movies ripped as MKV, and my PCH and Dune played them fine. The WDTV had issues with 2 of them.

I also noticed that the MKV movies that WDTV had issues where ripped with MakeMKV. I've read other people has had better success by using MKVMerge.

I have zero trouble with my MKV rips and my WDTV. Full Blu-Ray rips with DTS-HD audio plays fine for me.

On the kids Roku though, you need Plex, which will need to transcode in some cases.

See, I have an issue with your post. You make it seem like DTS-HD audio is working fine, but you are only getting the CORE out of the DTS track as it does NOT pass through the HD audio stream.
I have an issues (like gusgus) where some mkv's that play fine on my dune and pch units will NOT play properly on the WD live, but everyone's set up is different...

My apologies, I should have been more clear.

I don't hook my WDTV live up to any AVR (use it in the bedroom), just directly to a TV. For a surround setup I go with an HTPC for playback.

I haven't found a solution for $100 and under that can handle the variety of media that the WDTV does. I've attempted playing around with a Raspberry Pi, but it struggles with high bitrate MKV's.

Its pretty simple. You buy a WDTV, you hook it up, you try to play your MKV files. If it plays them, then you know the MKV will work. If it doesn't play them correctly then you know it won't work and you send it back.

In my personal opinion is slow, and at times it takes a few seconds to respond. It didn't used to be this way, but it became that way with the latest updates. I owned a WDTV for a few hours for testing, and thereafter I gave it to my parents. They only use if for Netflix and Pandora mainly. At times I usually lend them an external drive with a few movies so they can watch.

Based solely on the user interface and reliability, I'd go with a gen3 Apple TV and recode my rips to MP4 using Handbrake. The GUI for both Netflix and Hulu plus is second to none IMO on the ATV. Sure, some will disagree with the choice and encoding to MP4 is a PITA but the compressed 1080 BD rips with Handbrake stream so well.

I'd opt for the WD, I skimmed the thread but did not see mention of the ability of interface directly with a Hauppage Tuner. If you are doing OTA that may be a plus. Also it play s whatever I throw at it, has not stalled on anything. I have lots of MKV. files from makeMKV and it plays them flawlessly.

If you have an MKV that's been made properly, it will play. I've had one give me trouble and upon further examination the file itself was corrupted.

Most of my files are MKV's (I have my DVD's ripped to folder structure and the WDTV plays them, menu's and all) but I also have AVI's, WMV's, MP4's. The MKV's are made in handbrake(High Profile Preset) or MakeMKV.

Yes, the interface is a tad slow and it doesn't have the "channels" that a Roku has. But unless you're looking for more than Netflix, Hulu, Vudu, Pandora or CinemaNow (I do use the MLB.TV some) the WDTV live is perfect for the price.

The vast majority of files will play with the WDTV Live SMP. Netflix Hulu etc work pretty well. They stream rather nicely from a NAS as well. For the price you cant go wrong with the WD.