We are just buying a new flatscreen TV and 50 inch seems to be the standard now. One thing I do strongly suggest is to mount it on the wall. They are now getting a bit too big to put in the corner of the room. Also if you don't use a TV cabinet, this will free up a lot of floor space and make your room look and feel much bigger.
Most of these TVs now have bluetooth, and if your laptop has bluetooth, you can run all of your entertainment wirelessly.
I know you don't like messing around with the tech side of things, but if your TV seller has an instalation service as an add on, it is well worth paying for the guys to come and install it, they should also set up your bluetooth for your too.
If you want a wired connection that can be done too, but you will then need a small cabinet for your DVD player to sit on.