Ditto on Daly's Inn, decent pub lunch and not expensive.
Not so sure about the Newgrange Lodge place, looks from the outside more like an upmarket youth hostel, but the website pictures look ok. I'd still be inclined to go for accommodation in the D Hotel, for the bit of comfort and near to restaurants and pubs, and maybe have lunch in Daly's.
You don't really need to be staying beside Newegrange anyway, as long as you're just a short drive away.