Up until I got Gage, I had always wanted nothing but females, wouldn't DREAM of having a male dog in my house!!! But boy did Gage change my mind - and quick! He is my lap-baby, wants to be right there with me no matter where I am (sitting at the computer, laying on the couch, sitting on the floor - he's there!). Gabby, on the other hand, although she's a sweetie, she's not the "lover" that he is. She'd rather be left to herself and wants loving ONLY when she wants it! Gage was a "marker" until I got him fixed but now he's turned into quite the "squatter" when he pees. I've only seen him mark outside - he's pee pad trained inside and always squats and he'll also do his business outside.
As for your choice, you can't go wrong with either sex. But I can tell you, when the time comes for me to get another furbaby, I'm looking for a male - but that's my choice. Best of luck to you