Not sure what you would get for a hundred quid. I've got one of these
http://www.panasonic.com/uk/consumer/home-entertainment/home-cinema-systems/sc-hte80eb.html
Got it at Richer Sounds at the end of 2015, when it cost me £150 and I'm very happy with it. TV speakers are in the main, crap, so if you watch a lot of films as you say you do you will certainly notice a difference. Especially if the films have a lot of explosions...