Dun Laoghaire, Clontarf, Portmarknock, Dunlaoire, Bayside, Baldoyle, Louth and Sandymount.
Dun Laoghaire and Dunlaoire are the same town, different spellings. It's officially Dun Laoghaire. If you're interested in that area, most of the suburbs nearby are nice. Glasthule, Sandycove, Cabinteely, Johnstown, parts of Ballybrack, Killiney (much more affordable away from the coast), Stillorgan, Leopardstown, Booterstown, Deansgrange, Kill o' the Grange, Cornelscourt.
I wouldn't bother with Bayside. It's a little too close to Kilbarrack for my taste. Kilbarrack is pretty rough. Portmarnock is much nicer. Sandymount is nice, convenient to the city.
Check out Rathmichael/Shankill if you like the coast and value transport options.
lisney.com/neighbourhood/rathmichael/
Louth is way the hey out there. A very long commute.
I would go south if you were up for that amount of time commuting. There are lovely towns in Wicklow - Bray, Greystones, Arklow, Wicklow Town, Kilkoole, Rathdrum, or even Newtownmountkennedy - with rail/bus links to Dublin, access to the Wicklow Mountains and nice beaches in both Wicklow, and Wexford further south. Carlow (large college town) has a rail link and this might work too. There's also Newbridge, Kildare (town) and Athy on the same line (Dublin to Waterford) closer to Dublin.