What is the best brand of home theather systems?

im looking to upgrade from my 5 year old sony system(not that theres much wrong with i just want the new tech)

No such thing a best brand just what fits your needs best. Best thing you can do is go into a store with knowledgeable salespeople and ask them for help. Test their knowledge by asking for a system with high wattage. If they point out a home theater in a box with high wattage and try to tell you how good it is go somewhere else. They need to explain that wattage is not a true measure of sound output or quality, that it is a combination of sensitivity of speakers, power handling and stable continuous power with low distortion that determined volume and many other thing that determine quality of sound. They also need to play the system for you a moderate volume instead of trying to blow you out of the water.

If salesperson knows a thing or two he should start asking about the stuff you have and how you would like your new stuff to be different. He should also want to hear about the room it will be in and what kinds of things you like to listen to. Once he has all that he can make an honest and accurate recommendation. Once he make his recommendation ask him for 1 step up and 1 step down in quality and you now have 3 choices. Make him show you how the system addresses those things you spoke about then make your choice.

Without knowing any of those things I can't make a recommendation. Good Luck "Best" is relative. How much do you want to spend?