FTA is great if you have eclectic international tastes, as I do.
Forget it if you expect recent movies or premiership football.
I have a FTA system (motorised) and mainly use Hotbird1-6, Astra 2 and AtlanticBird3.
Have a look at
www.lyngsat.com to get lists of channels that are FTA.
For English-language only, there would be $ky News, BBC1-4, BBC News 24, BBC World, all ITV regions, after that very many shopping and 'God' channels.
If you've a foreign language, it's great for, for example 'ARTE' is just brilliant.
It's effectively impossible to get RTE, other $ky channels and Channel 4 on a FTA system. You could use the same dish but you'd need a $ky box and sub.