Stella's probably the closest she's had to a best friend among the team, but I also consider Danny her best friend as well. Just because they're married, doesn't mean they can't also be best friends. :)

Mac too,because on the episode(Life Sentences)he saved her from getting killed.

Anybody could seve her. I think Mac is like her father. Stella seems more like her best friend. When she had to go to Montana she told Stella first also Stella was the first person who learn about her pregnancy.

hmmm, i can agree with stella because she was the first person to know about what happened with her friends, plus she was the first person to give lindsay some advice and compliment when she first started working at the lab. then she sent lindsay the frame describing her bravery. but lindsay did mention that danny was her bestfriend when they fought about ruben's death.