For my money Spectre in Bishop may well be the perfect bouldering problem. Having said this I think there no such thing as a perfect boulder problem, and as such the only problem with Spectre is that it is 8b instead of 6b.
Only line up a huge boulder. Steep hard start on beautiful slopers up an smooth wall. Tricky moves to turn the lip and highball finish. All you could ever want.
Check out the vid. Bit of an ad for 5.10 but shows the problem well.