I went with eir for first year FTTH, install was quick and easy, service was good.
They messed up 2 months ago trying to charge me for excess usage, ended up over-charged 100eur, as credit, said it would take up to 60days for a cheque.
12 months now up. Rang to get a renewal, 30mins, and 4 transfers, so I hung up.
Just took 12 months with Vodafone €25 for 6 months / €60 thereafter.
All done via online chat (while on hold for eir).
The game is about changing annually for best price. I have separate WiFi Access Points anyway, so changing provider doesn't mean any new WIFI SSIDs or Passwords, their kit is just the router and nothing else.
The Sky deal is 24 months, but I trust them even less than eir.
No TV or phone line for me, broadband only deals.