I liked Leeroy Thornhill's early solo projects as well as his work under the Flightcrank alias. Although very different compared to The Prodigy, it sounded good. His work currently in Hyper is good too, but I prefer his older work.
Hell's Kitchen was a very good album by Maxim. Tracks such as My Web and Scheming, which both featured production work from Liam Howlett, are great tracks. Liam Howlett should have continued to produce some of Maxim's tracks, as I liked Fallen Angel less than I did Hell's Kitchen.
Flint was good, although the music did get boring after listening to it a lot. As for Clever Brains Fryin', their style was different compared to Flint. I prefer Flint, but must admit that I have never seen Clever Brains Fryin' live and only know two of their tracks, so it's hard to judge.
Of these three, I would say that I like the solo work of Maxim best, but it's a hard choice. I'm missing The Dirtchamber Sessions Volume One by Liam Howlett a bit in the list. That would have been my number one choice. It's a great mix of the music I grew up with.