Just in case you want to join in.
The most hilarious : Sengoku Basara
Not only is this series my first so it's special but, the actual historical generals were already pretty crazy, the ones from Sengoku Basara are from a completely different level. The plot is absolutely nothing special, it just has to do with beating up the bad guy, what's interesting is how they manage to get along (or not) to do so, given they all want to be the best and get rid of each others and all have a really peculiar personality. (Special mention for Akechi Mitsuhide)
Very, very, VERY loosely historically accurate but it is hilarious.
For fanservice amateurs : Sengoku Otome : Momoiro Paradox
That anime is "adapted" or I should probably say inspired from a pachinko game, which has obviously aroused suspicion in me but in the end, for an anime dealing with time warp that transformed all Sengoku generals into girls it's actually quite entertaining. Much more entertaining than Hyakka Ryouran Samurai Girls, which is another fanservice series.
The most accurate : Hyougemono
As you may or may not know Hyougemono is about Sasuke a teapot crazy guy who might be a complete invention, as well as some quite colorful happenings of the series, among the ones I have seen it's still the most historically accurate. Especially concerning the interactions between the different characters. Might be quite boring if you're not into it though.
The one you shouldn't watch unless you're a fujoshi and even if you are it's hard to bear sometimes, but it has big boobs so men can find something they like too and you probably should just read the manga if you're that interested because at least it has more perverted jokes and panels : Brave 10
I don't even know what to say about that one except that, while it got better after episode 6, you still should avoid it. But it has my favorite version of Sanada Yukimura ever so ...
My ultimate favorite : Sengoku Basara : the Last Party.
I'm cheating a bit because that one is the movie following up on the second season of Sengoku Basara but it happens to be the most hilarious of the series. The craziest one. The one with the better ED. The one with the better death, because only that series can make characters die not only once but twice and all of them completely epic. Also the one with my favorite death ever. And my all time favorite nabe scene. And, as usual, a seiyuu fest.
I still couldn't find the proper ED but, well, close enough?