Originally Posted by UAPremExecflyer

Your question is far too broad to be readily answered.
Dublin has a range of hotels from luxury down to hostel.
If your 'basic' days are behind you, what do you want to spend?
Also, not sure why you say "not many hotels seem to have king sized beds"?
There are plenty of them - here are five examples:
The Merrion
The Westin on College Green (beside Trinity College)
The Intercontinental in Ballsbridge
Jurys Inn in Christchurch
The Talbot Hotel in Stillorgan (a couple of miles out of the city)

Originally Posted by catcher1

The Clarion on the harbor (there are several Clarions, this one has a name, long one, starts with H--forgot whole name) is excellent. Rooms facing harbor and mountains; breakfast, afternoon waffles, dinner all included; excellent service; historic building; rooftop viewing platform accessible by circular staircase, actually an old bellower; and it's where the "action" is.

Originally Posted by Xnuiem

I have stayed at the Shelbourne a couple of times. (Ireland Hotel in Dublin City Centre The Shelbourne Dublin, A Renaissance Hotel). They have king size beds, very nice rooms, great location, and the breakfast was quite good. Lots to do within easy walking distance and of course catch uber to get anywhere else. Not the cheapest place though.

Originally Posted by LindaTerrill

The Merrion
The Westbury
The Westin near Trinity College
The Shelbourne

Some lead-in category rooms at some hotels will have a queen bed. Look at next category higher for a larger room and king bed.

http://bit.ly/DublinVirtuoso