I'm not an expert on this subject by any means but I get the impression if you want true surround sound you will always have to feed the sound straight from the source to the speakers before it goes to the TV, so you get the whole Blu Ray/DVD + receiver malarky and then can feed extra connections from Game consoles into there, now mostly digital. This gets complicated and often you will still have normal TV without that sound going through speakers unless the TV manufacturer has taken a connection possibility into account.
As a very simple solution (and audiophiles will probably cringe at this) I have hooked up my Sony Flatscreen straight from headphones out to a cheap (less than £100) Logitech 2.1 system. The sound? Incredible in my opinion, especially with Blu Ray. The thunderous bass is bloody fantastic on these Logitech speakers. I'm getting the same effect in Donkey Kong Country Returns on the Wii which is quite surprising. Whenever the gorilla slams the ground, it makes the house tremble.
This also lets me control all the volume, from everything TV, Games, Movies etc, straight to the speakers and the TV speakers are of course instantly disabled (and the Sony ones are crap too).
Perhaps a 2.1 system worth considering
here (it will do the same as what I have but you need a 3.5mm to RCA cable I think if it is not supplied) if you are interested in this cheap simple solution.
For me surround is not necessary and I don't want cables throughout the room. If I could get a wireless surround system I would consider different connection possibilities but for me this 2.1 solution is great at the moment.