It's Baldur's Gate II + Throne of Bhaal with some extra content.
They took an awesome game, re-released it for modern systems and displays but didn't change anything about the gameplay. That's a very good Idea.
Deep combat/character system (AD&D rules with a few tweaks), fantastic story, decent presentation, great and varied characters (it's Bioware, duh!), extremely well-executed open-world gameplay (after the first dungeon).
Release-version somewhat buggy, crashes, quests getting stuck, saves MAY get corrupted if game crashes on save (not terrible if noticed immediately).
You can get BG1+2+addons for less money than the BGII:EE, but that involves more trouble to get it running properly and is overall not just as well-rounded as the EEs.
Bugs are being fixed one after another, eventually it'll be just fine.