Devil May Cry series or NInja Gaiden series.

[youjiro]

dmc to me is more fun while ninja gaiden is more of a challenge. i loved the first dmc out of all of them because it was fun but the difficulty of the game was quite challenging as well.

as for ninja gaiden its a really tough game and played the first one on the xbox. i loved the challenge that it provided.

but the answer the origional question i'll go with dmc because i've played more games in the series and find it more fun