it all depends on what your requirements are for "best."

the H22 is a pretty good engine, but from a modification standpoint, the FRM makes it difficult to upgrade the bottom end without sleeving. the stock block can handle 8psi of boost before falling apart. It's kind of heavy compared to a b-series. Other engines, like the SR20det or the WRX plant yield 40 hp gains on simple mods. b18c5's have crazy hp/liter ratios.

OR

the h22 is a torquey high hp motor that is very capable esp in lighter cars. etc etc. it all depends on your point of view. but for closer to stock h22's it's a reliable, powerful engine, and that deserves alot of credit.