I found if you put all the dlcs together they don't last long does any one else thought this way and the serria mandre is my fravoite by a long shot but than lonesome road I guess.

I think it depends partly on how thoroughly you explore each DLC.

HH can be super short if you shoot the right person , fairly short if you just do the main questline, quite a bit longer if you explore every cave and location.

DM varies less in length, as you can't deviate much from the main quest. I explore every area after the main quest is over, which adds some time.

OWB takes awhile to finish the main quest, there's a lot of extra areas to scrounge through during or after that.

LR also varies less, you have to "follow the road" for the most part, there are a few side areas to scrounge if you want.

As to favorite, DM hardcoe FTW!