some bands wear their influences on their sleeve
rush is an obvious one. lee and lifeson loved led zeppelin. peart loved the who. they put them together and slowly found their own identity, metamorphosing into a prog rock behemoth.
dream theater was also obvious about their influences. all of the band's members loved rush. many of their songs are also reminiscent of other bands. the vocals and riffs in Constant Motion resemble metallica. Never Enough tries its best to sound like Muse. The Great Debate borrows concepts heavily from 46 & 2 by Tool.
Tool is a stranger case - one of those bands that has "their own sound" and doesn't really have any obvious influences. their music in the early '90s has the introspective lyrics and wiry production of a lot of '90s rock and metal, but their riffs were different. the guitar was grinding and mildly funky, the bass was turned way up, and the vocals were a unique mid-ranged clean style.