The first 10 albums (through Drama) have only 60 songs. If you omit the first two albums, it's only 44 songs on 8 albums. I think that, like you, Ben, most all of us know the first Howe-era albums intimately.
Then you have 38 songs on the 4 Rabin-era albums. I suspect most of us have a pretty good grasp of at least 2 of these albums.
9 songs on ABWH, which I'd be inclined to include.
7 more on the Keys albums.
Then there are 68 songs on the 7 post-Keys albums (plus From a Page).
So...that's 182 songs to pull from, but I think only a small handful of people are really knowledgeable enough on the post-Rabin albums. There's no way I'd do a top 100 and probably wouldn't do a top 75. I think 30 might be the right number, but I'd do 50 if that's what most folks want. I could also do what Kev did with Queensryche and limit it to the pre-Keys catalog.