[SixOfSpades]

There are indeed times where the game can get boring, and even irritating, and you mentioned 2 of them, Witchhunter: You'll run through the early stages of BG1 at least 20 times, and you can only clear the Nashkel Mines (with its dozens & dozens of worthless Kobolds and annoying Traps) so many times before it just makes you gag. And the atmosphere of Saradush is so hostile, coupled with its narrow streets that make it difficult to walk around in, yada yada. But really, the plot is mostly interesting both in BG1 and BG2 (not ToB, sadly); but you say you've already beaten them both before, so if you want new experiences, you should play a different character, do different quests, and use different NPCs. Therein lies BG's replay value: exploit it.