I have to go with ISOT as it was the first album I heard from them but I do love TIC. I really like how the samples with the preacher blend in and add so much to the feel of the album. There are some tremendous songs on that record and it flows very nicely.
Same story...in Search of Truth. Inner Circle album has excellent songs, but ISOT sounds better!
The overall sound is perfect: guitars, keyboards, drums, bass, vocals... ISOT is the perfect dark/prog cocktail.