Growing up in the 80's I watched a lot of TMNT and always felt a personal affinity for his brains and level headed approach.
Donatello is typically the calm, logical Turtle. He is often in good terms with all his brothers and seems to be very close to Michelangelo. His favorite music is classical & classical rock, his favorite book is A Brief History of Time by Stephen Hawking. Donnie is described as the "brain" of the TMNT, he is fairly studious and industrious, and a reasonable "Mr. Fix-It". Donatello has a knack for inventing cool new gadgets and machines. He is considered the most reserved out of the four turtles. He would rather talk things out than fight and uses violence as a last resort.
Though he is often portrayed as being more focused on his studies than ninjutsu training, Donatello has shown himself to be a very capable fighter, in particular, when he is in a life-or-death situation. He can set up plans as quickly as Leonardo, if necessary, though they usually center around one of his inventions or something else that would bar Leonardo from knowing the ins and outs of the plan in question. It is presumably for this reason that Donatello is often viewed as the level-headed second to Leonardo's command.

As any fan of the show can tell you the ninja turtles reside in the sewers where they train with master splinter to fight the evil Shredder. The coordinates will take you near the entrance to their home. You will likely find that Donatello and his brothers Leonardo, Raphael and Michelangelo are not home. Donnie however left behind something for you to record your visit. If you are (or were) a TMNT fan then tells me which character is your favorite in your log.
Permission granted for this placement.