I find personally that once you've committed yourself to playing an hour or so of it, you don't mind the graphics, and instead become immersed in the story and setting of the game. I would also say, that BGII is a far greater game since it has more focused story, and in my opinion, more memorable and unique main quests, subquests and characters, and it also has a more serious tone than the previous game. Though BGI is a good game, I do really dislike the amount of goofy "Monty Python-esque" NPCs you encounter in BGI, since I find it really it detracts you from the setting of Forgotten Realms, but BGI was BioWare's first venture into the FR setting.
I can also say, that I personally started with BG2 and completed it without ever having completed BG1 (though I've played a sizeable chunk of it), and I had a great time, and I didn't find myself lost at all with references regarding what happened in the first game, since everything of significance is pretty much explained by the NPCs. Also BG2 has a different antagonist and is set in a different part of the Realms, so it is really accommodating to anyone who hasn't played the first game.
