well for a long time I was actually going for boths and splitting my nights between both but they forced me to make a choice and I went for Morrigan ( but Leliana is still for the taking if I want,Leliana made me choose and I picked Morrigan then 30 minutes later after one chat with her she was again in love with me and this time Morrigan made me choose..)
ps : Morrigan is easy to sleep with me, it's quite alot harder to have her fall in love with you ( but the conversations she initiates as she slowly falls in love with you are quite cute).