FindMyPast.ie has added a family tree builder on its site.
I've just tried out the new software, and it's very easy to use, so even if you've struggled with tree builders on other sites, you might like to give this one a go.
As you'd expect, the software allows you to add, edit, update and delete relations, and to add partners, parents and children. You can view your immediate family, ancestors, descendants or whole family tree (see the picture below) at the click of the mouse.
In addition, you can upload photos and link them to your relations.
I've tried similar sites in the past, but I particularly like this one because the interface is so uncluttered. Looks good to me.
To try it out, go to FindMyPast.ie and select the Tree button. You need to register with the site (which requires only some basic personal details and a valid email) but can then start building.