Which are the toughest and coolest US Forces?

[JosephK]

Of the units the public does somewhat know about, isn't Delta/CAG comprised of only the best from other units like SEALs and Rangers?

Delta and whatever the CIA's covert forces are called have to be up there.

Army Special Forces, including Delta almost always include Army Rangers-- being a Ranger is an unofficial first step of becoming SF; but as a CAG, a Delta operation will likely include members of other SpecOps groups like SEALS... so, yeah, but not specifically.

[Slavic Italian]

Of the units the public does somewhat know about, isn't Delta/CAG comprised of only the best from other units like SEALs and Rangers?

No.

[NSXD60]

The new tranny trainees, whom, we're assured, won't suck.

[Westbrook]

No what?

No.

[Voskos]

Marines

[Jana]

Marines

Marines aren't elite unit though, and for some reason they are heavily overhyped. They do have their special forces though.
Generally dumbest types go to Marines, as they don't attract the best (poor job diversity and worst living conditions), even though there are exceptional prospects who join for the reputation they still have.

Source: military recruiters been vising school I attended in US quite a lot and some of my former classmates joined.

[Arūnas]

US forces forced me to dislike them, those who station in my town

[Voskos]

US forces forced me to dislike them, those who station in my town

The most bizarre thing I've personally witnessed is British soldiers beating up Marines . Happened in Greece, as incredible as it might sound.

[Voskos]

Come to Greece and see all sorts of armies parading , except the Greek one.

[JosephK]

The most bizarre thing I've personally witnessed is British soldiers beating up Marines . Happened in Greece, as incredible as it might sound.

US Marines tend to be creeps and assholes. Something about the attitude required to be a Marine. I'm glad to hear they got beat up by Brits.