You specify a smart TV. When keeping to a budget of £600 for a 50 inch, you might have to compromise on some other features, like Freeview HD or LED backlit. Before you plump for smart TV are you clear what smart features you really intend to use? For example we have A Sony smart TV which has a lot of disappointing features. It has an internet browser that is as much use as a chocolate teapot. It's clunky, impractical has no keyboard except on screen, VERY frustrating to use, so I never use it. It's other internet features are at the mercy of Sony who provide a list of entertainment sites such as Netflix Sony Entertainment and other pay per view sites. There are quite a few free sites like YouTube , Break and lots of other less well known sites which I'm not inclined to visit. The most useful feature is BBC Iplayer but that is a cut down version, not as good as you get on a PC. You do of course need an Ethernet port near your TV or a wifi adapter or a home plug to enable you to get internet to your smart TV. This may come at an extra cost.
If you have a sky HD box and a home cinema system and a separate Blu ray player, you'll need three HDMI ports.
If you tell us what features of a smart TV you definitely need and intend to use that may help in narrowing down your choice.

I get catch up TV as part of my sky package which means I never use the smart features of my TV.
I have Freeview HD built into my TV which I use occasionally when my Sky box is otherwise engaged recording two other channels. However I think there's only the top 5 channels currently doing Freeview HD.

Ideally you want 1080p display (full HD) , LED display, 100 hz refresh rate, Freeview HD, wide angle clarity ( clear bright picture seen from the side , not just in front, low standby power, three HDMI ports , decent sound speakers unless you will use a cinema audio system. The latter needs you to actually see and hear the TV for yourself. If you can get all that including smart features in a 50 inch £600 TV you'll be doing really well!

I have a Sony Frank and when we bought it coming up two years ago we were told they were adding ITV player by Christmas I assumed it was the one about three months away, wrong it is still not there and another Christmas has come and gone

Although my SonY TV is now 4 yeas old, last year I bought their Smart Blu Ray player. It has all the same Smart features of the older TV and is just as useless to me. If anything the internet browser is even more frustrating, slow and infuriating to use.

Edit:- now there's a thought. You can turn any TV into a Smart Tv by adding A Smart Blu ray player.

Shrimper, no - ours hasn't got ITV player either but we do have demand 5. It's worth checking for firmware updates via your home screen. Anything they add will probably need an update.

Babs135, this ticks all the boxes at £599 for me except the 50 inch one, it only has two HDMI ports which you need to bear in mind. It's a 48 inch but has a five year warranty and built in Wifi included. It's cheaper elsewhere without the warranty. Check it out...
http://m.johnlewis.com/mt/www.johnlewis.com/samsung-ue48h5500-led-hd-1080p-smart-tv-48-with-freeview-hd/p1451296?un_jtt_v_pdp=yes&un_jtt_v_from_product=un_product_1#page_loaded

Argos has a few 50 inch smart tvs for sale for under £600. There's a Sharp for 549 pounds with 4 hdmi (needs a dongle though if your using Wifi to connect to internet). There's even a Bush for £349

I bought a 51" Samsung a couple of years ago and deliberately DIDN'T go smart! I use a laptop attached via VGA/Stereo input to give me "smart" features and I have a hard drive permanently attached with a large number of films and TV series on -got that set for less than £450 with a 5 year guarantee!

You need to see the picture and hear the sound before you make your choice, you'll probably get what you pay for.

Agree about the picture..but sound?...its worth paying slightly less for the TV and rigging up a connection to a soundbar or sound system ..infinitely better quality than any TV built in speakers.

Yes I agree with you Brewerdave. I have a home Cinema system for my sound but for reasons of energy saving we only use it for movies, major sporting events and top Tv series. It helps to have decent built in sound for other occasions .

Thanks for the help. Have decided to wait for the Xmas sales as we need a new car more than we need a tv!!!!

On the subject of Sony updates, shrimper, I recently discovered that my Iplayer app on my Sony TV could no longer connect to the BBC server. After a bit of research on the Sony site, I discovered that it was a known issue which required a firmware update to cure it. I don't know what your model is or if it was affected, but the information is here. http://www.sony.co.uk/support/en/content/cnt-hn/prd-tvhc/improve-the-BBC-iPlayer-performance.

Note I had to download the update to a USB stick and manually install it, since the auto update on my TV would not recognise that there was a newer update.
The Iplayer now works, but this version will not play HD content.

re Frank's last post:-
1. Make sure that you have the correct update file for your particular model of TV. Some websites are VERY confusing with firmware updates, and there are frequently different update files for very slightly different models.
2. Follow the update procedure precisely.

If in doubt don't do it.

They are many tales on specialist forums of people who have "bricked" expensive TVs attempting an update, and have had to pay large sums of money to get the manufacturers to put it right.

Good advice, Brewerdave. I realised why my auto update feature never works. I have one of those energy saving plugs (standby savers) that actually disconnect TVs from the mains when you turn them off. I discovered on the Sony site that updates generally turn up when the set is on standby, and my TV never was on standby.

a maximum of £600

.
http://www.bornrich.com/harrods-sell-panasonics-152-inch-tv-600000.html

Then I realised you meant £600 not £600 k

Found this on offer including 5 year warranty.

http://www.costco.co.uk/view/product/uk_catalog/cos_1,cos_1.1,cos_1.1.6/166904