Here goes...
Obsession v1 - ridged sleeves
Blue v1 (blue sticker) - Blue Extreme
Green v1 (green sticker) - Green Extreme
Black v1 (black sticker) - Black Extreme
Red v1 (red sticker) - Red Extreme
For a *very* short period when the obsessions first came out you could also choose to have either a blue, black or red sleeve. I'm sure I recently posted a pic of these, but I can't find it at the moment. <edit: found it...
Re: Post your collection>
You choose the combination of maze / sleeve. Logically you'd have:
a blue maze in a blue sleeve
a black maze in a black sleeve
a red maze in a red sleeve
and a green sleeve in a black sleeve (as green sleeves never existed).
However, there was nothing to stop anyone ordering a red maze in a blue sleeve, or any other combination. The only way to identify the v1 mazes is by the sticker on the end.
To make things more confusing, when the plastic mazes first came out, for a few weeks/months they were called "Extreme"s while the original metal versions were called "Obsession"s. Clearly this was silly, so one day, the names were magically swapped. Therefore, very old threads may refer to the plastic mazes as extremes.
Obsession v2 - smooth sleeves & removable core
Blue v2 (blue sticker) - Blue Extreme
Green v2 - ?never existed as far as I know?
Black v2 (black sticker) - New black maze - not the same as any extreme
Blue Pro v2 (red sticker) - Blue Pro (similar to a Blue Obsession/Extreme but must be solved multiple times)
Obsession Level n - essentially identical to v2 obsessions
Level 1 (blue sticker) - Blue v2 / Blue Extreme
Level 2 (green sticker) - Black v2
Level 3 (red sticker) - Blue Pro v2
I think?