Defenitely don't take R.O.B. to BF, it only makes his camping all the better...and maybe some other shizznit I can't think of...
For neutrals, it seems that Lylat Cruise is the best option, the tilting screws up his projectiles, and the tilting of the stage mgiht distort his auto-sweetspotting with the booster recovery. Not only that but killing also becomes much easier here with the blastzones so close to the stage.
For counterpicks, I wonder what would be the best option though...I'm thinking...Frigate Orpheon, Castle Siege, dear I say...Green Greens! What else...hmm...no, from the top of my head, those seem to be the best options. Frigate Orpheon kind of throws R.O.B. off his groove becauset he stage is small, one stage doesn't have the ledge, making R.O.B. all the more easier to gimp, and the second stage is...meh.
The first stage of Castle Siege is extremely small, no way Gyros/Lazahs will be too useable. The second stage stops gyros in place...too bad Lazohz still go through them...but anyway just don't let R.O.B. grab you here. Some things here can either encourage or disrupt camping. Moving on to the final stage, it's basically just a FD with a tilting stage. Green Greens(treet) is self-explanitory.
Roy's sig is too good.