Minecraft.
Love it or hate it, it drives a lot of traffic to our site. Sure, recently we've had some bother with modded tech support questions, but overall, most of our questions/answers are fairly high-quality, and this is reflected in the substantial upvotes, bounties, views and comments on a lot of our questions (and answers).
Minecraft has been moving steadily onward, and as bugs were fixed or functionality was added/removed, we too updated questions, modified answers, and closed and deleted those which were no longer relevant.
Since that time however, Mojang has added the ability to select and load old versions of Minecraft from the launcher. Is that enough incentive to undelete well-written, well-maintained questions and answers?
For example, we have this question (10k+ only): How short can a minecart booster be and still be effective?
Minecart 'boosters' were due to an errant bug in the physics of how minecarts interacted with one another, which was fixed in Minecraft Beta version 1.6. With the ability to select a version prior to this, such as Beta v1.2, this question and answer is relevant again.
Should we vote to undelete this, and questions like it? (If yes, should a disclaimer then be added to the answer that states when the bug was fixed)?
Screenshots of the aforementioned question for those under 10k rep: