As the title says, i really wish to find a good tv show series as good as cowboy. And what i mean by that is:
- Adult themes
I've tried to watch Trigun, but its too stupid and damn uninspired. Its basically for kids and i can't watch that kind of crap.
Well, i'm a huge fan of Sci- fi, and Bebop was to me like a second Mass Effect (not a good comparison, i know). Anyway, this is not obligatory
Well written and most important serious at times. I said already that i can't stand for characters like Vash the Stampede, to me they're not funny and look just stupid.
You can try Psycho Pass but that show has some weird dialogue. Gankutsuou is also really good, and fits your criteria, but I'm not sure if you are looking for an action show or not, but it is sci-fi. Ghost in the shell stand alone complex is also really good.
You can also try Evangelion Rebuild movies and Gundam Unicorn both of these are mecha but both are extremely different, and are pretty serious shows.
As for non sci-fi related stuff you can try black lagoon and Samurai Champloo. Both of those are more light hearted but they have their serious moments.