there are generally a number of things to consider.
some of the main ones are:
is your room very bright or average to dark?
will you be using the tv with a game console / as a pc monitor?
will you be viewing mainly head on or from fairly wide angles?
what type of content will you watch and where from, i.e. regular broadcast tv, streamed services like Netflix, cable tv, set top box, dvds, blu rays etc.?
and as a matter of interest can you say why you would like to stick with Samsung as of course that will narrow down your options in terms of models and tech.
tvs are generally pretty thin and look good on stands and wall mounted.
at least with your budget there should be some great options.