What is the main difference between the Maine Coon, Siberian Forest cat, and Norwegian Forest cat? I only know of small differences and I can't distinguish them easily.
Here's a nice comparison table I found (taken from here ):

Forest Cat
Maine Coon Cat Siberian
HeadEquilateral triangleWedge shaped with a square muzzle Broad, modified wedge with gentle rounded contours
Nose ProfileStraight, no breakGentle curve Nose has a slight curvature and the lower portion to the tip of the nose is concave.
EyesAlmond shapedLarge with open expression Large, almost round.
EarsOuter edge of ear
follows the line of
the head down to
the chin completing
the triangle.
Set high on the top
of the head with not
more than a ears
width apart.
Set high on the top of the head with 1 to 1 1/2 ear width apart.
BodyMedium in length,
square in the
Long and rectangular.
LegsHind legs are higher
than front legs.
Medium in length Moderately long, slightly rear legs longer than the front legs
TailLong and flowing,
as long as the
body, circumference can reach 12" plus in
Long and flowing, as
long as body, not
as bushy.
Wide at base, blunt at tip. Even and thick long hairs drape down from the top side of the tail.
CoatDistinctive double
coat, long guard
hairs covering a
thick wooly
Silky, shaggy, uneven
coat with a slight
Moderately long to longhaired.
RuffWhen cat matures, a
profuse ruff develops
around the neck.
Moderate frontal ruff
around the neck.
Mature Size/AgeUp to 15 pounds,
Females age 3
(7-10 lbs.)
Males age 4.
(10-15 lbs.)
Up to 20 pounds,
Females smaller,
Males larger.
Not given

There's also this interesting drawing (taken from here ):

the main thing in their looks is that the Maine Coon has long ear tufts and as far as I know is the only domesticated breed with them (current me if I'm wrong, I don't have any other breed that comes to mind atm) . The Maine coon is also bigger. The main thing though is something that most people wouldn't be able to tell unless they know the breed very well which is differences in the face (eyes, noes, head, profile) and body shape, it's like finding the difference between a Korat and a Russian blue, unless you are really familiar with how their face usually looks most people wouldn't be able to tell the difference.
Thanks! Emotion: smile
 Prada's reply was promoted to an answer.
nice! thanks a lot Prada! Emotion: smile
You're welcome, I'm always glad to help if I can.
Pixie bobs and American bobtail s both have earned tufts.

Hi, I would like to adopt this cat and would like to know what is his closest breed (it was found in the streets so it might be either a pure breed who escaped and never found/ or was left on the road, or a mixed breed). Thanks!