In Flames all the way...and I agree about Whoracle as well

These two albums, to me, represent the high points in the band's catalog. Whoracle is my personal favorite.
If you happen to like both of those you may also like Colony. I don't like it quite as much as the other two, but it was a strong release IMO, even though they butchered Iron Maiden's "Murders in the Rue Morgue"(bonus track only), which is ironic given how influenced they are by Maiden. Clayman is also very good but also rather spotty - I personally see a notable drop. These days they aren't bad, but it's really been hard to get into their last few releases.