Audio/Video Chat → DTS or PLII(movie/music/game) upmix

What is the best thing to use to upmix and 2.0 Stereo signal to 5.1 Surround?
I am trying to figure out the difference between these two settings.
The 2.0 stereo feeds that are coming in to my stereo are:
DVD (stereo encoded audio)
computer (mostly 2.0 PCM audio)
FM (2.0 stereo broadcast)
I find with DTS for FM you really need to crank the center speaker up to +5dB. Also I find that PLII Music is a lot more loud.

It really comes down to personal preference. Use the one that sounds best to you. For music I like the 5.1 stereo option that just copies the l/r channels straight to the rear and center. For other 2 channel stuff i use PL2 movie mode.

I guess that would be 'all channels stereo'?

Ya, different names from different manufactures. Denon calls it 5.1 stereo.

pro logic 2 to simulate 5.1

My Onyko calls it 'all channels stereo' and my other Pioneer calls it 'EXT.Stereo'

Sometimes when I playback an video file on my computer with VLC media player that has DTS encoded audio, my receiver lights up the dts light.

I like PLII.

Is it not suppose to do that?

Based on my experience, that's normal. You should get an indication on the Receiver for the type of signal that it is receiving. Should be indicators for DTS, DD5.1, PCM, etc.

I use "All Channel Stereo" for stereo music sources and PLII Movie for two-channel TV and movie sources.

I think so. All though I never used an PC with HDMI on the receiver before.

PCM for everything. From the POST screen, to the desktop, and even for my games.