ITP has the most amazing drums/bass parts of any metal record ever, imho. Symbolic is the easiest listening of the three, and some of its songs are carved in history forever (1,000 eyes, symbolic, without judgment... etc) - but I remember buying TSOP and giving it the first spin, hearing my jaw drop to the floor and think "ok, so this is it. The record to end all records

". That was a bit driven by the emotions of the moment, but still I can remember that day. Oh, and to get to track n°6 took me a couple of days, cause I kept on listening "flesh and the power it holds" over and over and over...
Chuck was still far from his sad passing, but you could already say that his sorrow and sadness were flowing thoughout the whole record.. While "Painkiller" did what usually can't be done: take a legendary song and make it DOZENS OF TIMES better. Something that just Chuck could do.
To sum it up, however, I could not choose a better record off the three - I'd take a bit here and a bit there.
And as soon as Muhammad Suicmez starts singing a bit higher than his deep growl, we'll welcome Necrophagist as the one and only heir to Chuck's legacy, I can bet my house on it.