Robin/Grayson from BTAS was pretty damn great. For me, that has always been my favorite interpretation of Robin. I also liked the idea of him helping Batman when he was older, in college. That made sense to me.
"Robin's Reckoning" is one of the best episodes of the series and shows why Batman wouldn't just "work alone". Wayne relates to the kid, takes him in. It makes sense to me.
Do I prefer a darker, solo Batman? Sure. But that sort of Batman starts to get old after awhile. Robin is as important and iconic to the mythos as Joker, Catwoman, etc. He's just a year younger than Batman as far as first appearances ago and has lasted for 70 plus years. I'd say that's a strong character. The "Dynamic Duo" and that image of the two of them is as iconic as "The Dark Knight" or the "Caped Crusader".
As far as Arkham City goes. Hooded Robin didn't do much for me. Most of the recent Robin interpretations haven't. I hated "Robin" Blake. If you're going to utilize the character, don't be afraid to dive right in and use it to it's full potential.
Also, Robin is the only ally of Batman I'll take (along with Alfred and Gordon obviously. I hate that "Bat-Family" stuff. When you start having multiple Robins, Batgirls, Batwomen, Azrael, Spoiler, etc. etc. it gets a little weird.
For me, Robin (Grayson), Alfred and Gordon are plenty.