ditto, except i wouldn't really care for the playoffs either if the rockets didn't exist. the big 3 will ultimately be fine. the obvious answer is probably the nhl.
If Donaghy flips and cooperates with the FBI in the investigation then I feel he could possibly implicate other refs or quite possibly players. This could only be the tip of the iceberg so to speak, something that could damage the legitimacy of the game causing fans to walk away.
I would vote for cycling if it was an option, IMHO no sport is in so much trouble as cycling. I'm not enough into american sports to make a good judgement about this. However i think this whole Ref thing can really turn into something nasty for the NBA.
Of the big ones, definitely baseball. It's audience is shrinking and getting older, most games are boring when played right by unenhanced players, they have a loon for a commissioner, a stupid all-star game determines home field in the Series, half the teams play by different rules, and a steroid user is about to take the greatest sports record in American history yet nothing will be done until after the fact. Ripken was probably the last "baseball" moment I had any real interest in... it was clear to me at least that Sosa and McGuire were up to something. I did follow the Astros' run to the Series, but it was based more on childhood nostalgia then any love for the game or the team.
But they'll be back. I think it's the NBA without question. If this comes out to more than one ref and/or players, that league is in serious trouble. It's already a joke of a league when it's apparent that some players are not treated the same way as other players based on their star level and anyone can draw a foul by acting like they were shot when they weren't even touched. The product right now is terrible and the proof is in the audience, or lack thereof.