If you're mostly watching broadcast TV, then it's going to be 50Hz material anyway. I'd stick to 50Hz.
That said, and regarding your recent comment, getting something with a network connection in it (wired or wireless) is a very good idea.
My 2010 model Sony has iPlayer and various other free and subscription services in it, and I like at least some of these. The iPlayer is particularly nice.
But also, the TV is DLNA compatible, so it can access my media server computer fro the TV's own menu.
I run a free program callled Serviio on the PC, and have my own tv recordings there, as well as DVDs I'm watching. I find the upscaling of DVDs far superior if I view them through the network DLNA interface than if I play them on my upscaling DVD player. They can look quite impressive.
On Windows 7, you can right click on a video or MP3 file, and choose "play to", and it'll play out on the tv. All quite fun.
There's
lots to tinker with!
DLNA website
http://www.dlna.org/ - you can serach for certified devices.
Ian