These animes were selected after seeing some lists of mature or seinen anime, and then look for reviews for them. Most have 4 or 5 stars, and some interesting promises, but for Btooom! This is more of whim, since it is from Madhouse and appeared in the search.

One reviewer said to stay away from kaiji if you don't like manly tears with long comedic monologues. Let's see what I think of this.

I haven't heard much good about Btoom.

it was fanservice and half-believable shounen action and was unfinished

i thought it was okay

I don't recall much fanservice, personally, just explosions and a terrible premise that went nowhere.

no need to be scared if you want i will make some references to things that nobody but me will get and that can lighten the mood

I didn't see any review of Btooom! at my favorite sites, but two others give positive reviews, many users also give a positive review, and it has a rating of 4,5 of 5 at crunchyroll. Not enough to be considered good, I agree, but it is also from Madhouse. So I will probably give it a try.

I don't understand the problem of fanservice. As long is nothing really disgusting or is the whole purpose of the anime, I don't care much. Everywhere you look there is some kind of fanservice, with exactly the same purpose.

I find that a lot of people who cry "fanservice!" will do so regardless of context and you don't need to listen to them. It is, however, a problem in some anime where, as you say, it isn't supposed to be the focus. The unnecessary ogling of the female characters is the entire reason Sword Art Online is so bad it's good; and I can remember some rather odd/awkward moments in Code Geass that also didn't need to be fanservice-y.

I only mention fanservice because it was particularly heavy in fanservice as far as i remembered. I don't really like having topless women shoved in my face but i can tolerate certain quantities of it without being annoyed.

4 episodes into Hakkenden, Eight Dogs of the East.

Good so far.

The purpose is clear enough, boost sales. Code Geass is a shounen anime whose target audience are male with 15-18 years.

Code Geass is good example for this matter. It has a very low amount and it doesn't need any fan service to work, but it has to appeal to that audience. In its case, more so, because it was designed to appeal to almost everyone. Or Elfen Lied, for example.

It is bad because of that, certainly no. It is the same thing of you going to a movie with Scarlett Johansson and she appeared nude in a scene, the movie will be worst because of that? I would not complain , but I would not go to the movie only because of that, but there is part of the population that would go.

So it returns to my early comment, as long is nothing really disgusting or is the whole purpose of the anime, I don't care or think the anime is worst because of that. I have more problem with anime that fan service is the only purpose, like the one you mentioned, normally I cannot watch them for more than a few episodes. One example of this class that I remember is Queen´s Blade.

^^ The perfect example of that is Rosario X Vampire.

code geass is actually an interesting anime in that it has a very mixed demographic. It was originally an anime, and manga adaptations were run in magazines for three different demographics (shoujo, seinen, and shounen). The characters are designed in bishounen style which you'd usually find in shoujo manga, but there were some scenes in the show that did seem to pander to the male demographic.

I think btooom has enough content in it that I wouldn't call it an anime based around fanservice.

A lot of fan service is fine as long as it provides some value to the show other than "Hey more nudity". For example Heaven's Lost Property actually had a lot of really good jokes for a fan service anime that were unique because of how it went about things, and Is This A Zombie didn't exactly end up on my rewatch list but it wasn't that bad either. The real problem is when there's just lots of fan service there with nothing being done to add value or distinguish the show from the slew of crap that tries to pull this.

The only bits of Heaven's Lost Property has been from the AMV Hells or maybe one of its knockoffs, but the bits I've seen have been so out-there (like a flock of flying panties) that I figured it's probably worth a watch.

Are they still doing AMV Hell? I stopped checking in after the third one.

They've done... I think 6 now? From what I can remember, they're working on 7. My favorite was number 5, but that may have been the one I was introduced to it on.

Oh, and they had a lot of AMV Hell Minis, which were typically ~10 minute videos of ~30 second clips.

I know they did AMV Hell 0 as well, which was just kinda off-putting.

I don't understand how that is possible. A little fanservice that don't take time from more important facts, like an odd camera angle or some lost scene, is fine, but I don't see how a lot of it can leave space without hurting the own anime.

A lot of it, when it actually lends to a unique sense of humor or something else that makes the anime unique, can be a good thing. There are a few things I've watched that have managed to pull this off well just by making me laugh my ass off despite myself. And........ a hell of a lot that didn't. Much more often than not a lot of fan service is a very bad thing as far as quality goes.

Because there is not necessarily relevent content to fill that space the fanservice takes up. You could argue that instead of fanservice, they should be trying to perfect techniques to make better use of the content they have to work with, but at the end of the day what matters is that the content is there. If the fanservice isn't detracting from it, I don't have much of a problem with it.