So, which chapter or chapters are most common/uncommon in games you were in one way or another as mentioned in the title?

I must admit that as far as my games, that chapter was Space Wolves, concerning the most common. This guys are very much liked and in my current game I have two of them. One is a Wolf Scout and the other one Runepriest. I have no problem with that, as long as players enjoy their roles and characters, but there is a Wolfy trend amongst the people I know and rarely was there a discussion that didn't involve them
Saying that, the least popular are Storm Wardens. Never have I heard players expressing their wish to play them. Not sure what is the reason exactly, maybe they don't like theirs "philosophical" nature or something. The fact is; they are rarely mentioned and are never played.

Before "First Founding" was released the most powerful character in our group was a Storm Warden Tech-Marine. Each of the specialties seem to cater towards a different chapter. The Assault Marines where Blood Angels, The Tactical Marine was a Space Smurf (Ultramarine). Personally, I played a Blackshield Tech-Marine as the chapter that I wanted had not been released when we played.

Interesting. You have quite the opposite case than my players. I wonder how common it is that certain chapters are their own "best specialties", for example, BA are always assault, Ultras Tactical etc.?

Cardinal Nicodemus said:

It's relatively common. BA Assault, BT Assault, (Space Wolf Assault,) UM Tactical.

Alex

How about apothecary? It seems to me that Blood Angels fill that role more often than not. Especially now that Sanguiniary Priest is available. But, as far as holding secrets go, DA can make good apothecaries, so can BT for good melee orientation, Storm Wardens are good for durability, Ultras can be anything...

I guess what I want to know is; is there really a good reason not to be Imperial Fist assault marine? I mean, in the end it doesn't matter if you enjoy the game, but some choices are 'too obvious' sometimes.

My group has:

Ultramarine Tactical

Space Wolf Tactical

Ultramarine Devastator (Tyrannic War Veteran)

Dark Angel Devastator

Death Spectre Assault

Carcharodon Assault

Rainbow Serpent Librarian

Iron Hand Tech-marine

Blood Angel Apothecary (Sanguinary Priest)

Rainbow Serpents are pretty much like Ultramarines in most respects, so that makes Ultramarines and their successors the clear winners. Death Spectres and Carcharodons both resemble Raven Guard so that would hold the second place.

My first DW Kill-Team was:

Ultramarine Librarian

Space Wolves Devastator

Blood Angels Assault

Dark Angels Apothecary

In the current game we have:

Consecrator (DA) Librarian/Epistolary

Subjugator (IF) Techmarine/Forgemaster

Black Templar Assault/Champion

Raven Guard Tactical/First Company Vet

Both groups were faring pretty well, the only person complaining about his performance was the SW Dev, but that was before the errata that gave him free Counterattack Talent (also, the player has a thing for complaining).

As for optimization, it depends. I've mostly seen people talking about best Assaults and best Librarians, both in my group and here on the board. Assaults because melee combat is deadly (and thus a degree of optimization is advisable if you wish for your character to live) and Librarians because unique Psychic Powers.

What's important to remember is, all Space Marines start at "overpowered" and optimization only gets them to "broken" or "full Munchkin". So, it's not a bad idea to play an Imperial Fist Assault... unless there's a Blood Angel / Storm Warden / Black Templar Assault in the same team, in which case you might feel a little frustrated.