music maker and musician inc are probably the two best... they're on exchequer street and drury street, just a few minutes' walk off grafton street (one of the main shopping streets- it's probably the best one, to be honest, though o'connell street/henry street, north of the river, are ok too). There are another couple north of the liffey, but they aren't really worth the walk. Though one, away at the top of o'connell street (actually, it's further north of o'connell street) has those sx's that rondo sells, though i haven't tried them. But that's liable to waste about an hour if you walk from grafton street. To be honest, I probably wouldn't bother, unless you're struggling for something to do.
www.musicianinc.iewww.musicmaker.iewww.waltons.ie (apparently they have a shop in dublin 2 as well, so that may be worth a look as that'd be handier to those other shops)
you can hit up their websites for the addresses and then go to multimap or something, to be sure you don't miss them.
oh yeah, perfect pitch is almost right beside music maker, on the same street. it's not great, but you may as well take a look in while you're there.
EDIT: also, bear in mind irish prices are liable to give you a seizure. I use the dublin shops for trying, not buying.
