Looks like it may only be you and me DWV, who can actually comment on this. We may be the only people on this forum to have heard all these albums!
If we're talking BEST album, then that goes to
The Crimson Idol hands down. It's the bands (well, Blackie's) best work to date. For a concept record it is excellent, marking an even further step in maturity for W.A.S.P. and the musicianship is incredible.
If we're talking personal favourites, then my pick is
Inside The Electric Circus, as that album pretty damn much changed my life and blew my little cotton socks off from the first spin. It gets some heat, but the production is great, the riffs are real mean and crunchy and the lyrics are fantastic.