Hands down, BCI or BCC all the way.....or a retic. But then again, I'm biased towards those two. Boas are pretty simple to take care of and even if you dont interact with them every day or even every week, they still stay docile assuming you worked with them as a baby.

And retics, Caesar is the only snake ive ever seen that i felt was needy lol. When he's not in shed, he is actually pretty social and always out at night sitting infront of the door i usually leave open for him like he's waiting for me to pet him. I slide the door open and he stands up, looks at me and then lays down by me while i pet him or he will lay his head on my arm. I know snakes dont have feelings like that but i swear Caesar likes the attention lol. If i wander away and sit down to watch tv, he will slide down the cage stack to the floor and explore lol.

I have never owned a blood python but since I'm limited to probably something like 10-12 snakes, there isnt enough room for stuff other than BCI, BCC and retic