ctrl f -> One Piece -> on hold -> here your problem
You should give One Piece another try gets better after episode 55 which is around where the 2nd saga begins.
On another note umm Samurai manga/anime
Based on your list you have not watched Gintama. It starts off slow but it gets really good. It is mostly comedy/parodies but it has a lot of action and a lot of serious parts.
http://myanimelist.net/anime/918/GintamaHere is an amv of some of the fights watch the whole video.
I have heard that Rurouni Kenshin manga is better than the anime and continues where episode 60 something left off.
Also did not see this in your list
http://myanimelist.net/anime/44/Rurouni_Kenshin:_Tsuiokuhen you should watch it.