Even though it's a work-in-progress for now, this is the most epic checklist up to date. It's got all the updates from previous checklists, but it's also been added to recently.
On the checklist, there's all the comics you should totally have. Superior Spider-Man #17-19, 23, 27-31. Uncanny Avengers #14, 18-22, anyone?
But more than this, it's the fact that they have a list of trade-paperbacks and hardcovers too. They even have a list of 2099 guest appearances in non-2099 titles. A list of advertisements with 2099 in them! Action figures! Video games!
Seriously, this list may not be complete now, but it's basically the best list we've ever seen. It's got so much stuff...