When I think of bugs in a game, I think of hilarious animation glitches, NPCs that don't properly spawn, or perhaps misplaced textures. Bugs are always going to be there, despite the best efforts of developers...but I find that my ability to excuse bugs in part depends on how much I was enjoying the game prior to encountering it. The paragon example in my mind is Skyrim. Out of the box it has some severe, sometimes game-breaking bugs, and I once played with them and enjoyed myself. So I got to thinking, why is it that I was eager and happy to play and defend Skyrim despite the bugs, when other games I would have completely dismissed due to a single or smaller bug.
I can think of a variety of factors...in one regard, Skyrim is open ended, so if I encounter a bug in one aspect I can often head to another. However sometimes that doesn't work, so I am forced to either patch or break into the console to fix the bug on my own. That there might be one reason; I can fix it myself. On the other hand...I think the true reason is that it was a game I was genuinely having fun with, it was one I didn't need to "justify" my fun for. With other games, encountering a bug might mean I quit and never open it up again. I think my passion for the game, how much I _WANT_ to enjoy it, might have an effect.
Originally I thought this up because of my experience with Firefall. I've been playing it with a group of friends lately, and we have a lot of fun when we're thumping or running missions together. This is in spite of the social-network occasionally crashing and kicking us from our party, in spite of the crafting interface sometimes refusing to work, in spite of certain mechanics sometimes not working or lag causing enemies to take no damage. One could say it even extends to glaring imbalances in the game that aren't necessarily bugs. This kind of list would probably doom most games in my eyes, but here, we keep playing and I look forward to the next time we will.
So as I write, I find it often comes down to how much fun I was having prior to the bugs, or despite the bugs (when they don't stop progress) that determines my willingness to ignore them.
What about you my reader? Do you find that bugs are more often just a bump in the road? Or are they more frequently game breaking? Does your passion or love of the game keep you going? Or is a critical bug a death sentence for your continued play?