Interesting Question!
Very interesting question.
My first response to this may sound negative against d20 but I don't know how else to say it.
In the end, I don't think that d20 will work for every genre. I think Spycraft has done a very good job of being a d20 game within a specific genre that works. It also had to redo many areas and make it specific to its campaign setting. That's fine. My point was that it took changes.
On to your show ideas:
Friday the 13th: I think this one is the overall best fit for d20 Modern. None of the main characters would be very high level, they probably don't have advanced classes and all of them probably have several levels of Smart or Dedicated hero. This is probably a good example of a Shadow Chasers type campaign with having the chosen one.
The only thing I can't figure is combat. There were many times that they had to resort to overpowering their enemy and it usually took all of them on *one* person to do it. In an actual game setting, the dice might betray them and make this more bloody than the GM wants.
TbaA: I don't know as I haven't seen the show. Won't stop me from commenting! *grin*
Could be that Angels are relative to humans as far as abilities. In that case, it would fit, although Tough and Strong would probably be out. Dedicated and Charismatic? XP then would be based on who is saved?
TP: No idea. Haven't seen it before.
Other shows.
Dukes of Hazard:

Yes, this fits with d20 Modern, probably very well. Weapons were rarely used and hand to hand combat lasted a long time, when it was done. Could be d20 Modern Lite!
Boston Public: Could be done but it would be pretty boring!
Law and Order: Obvious split between classes. Could be done, either playing one half or the other, but I would think the Order side would get boring as it is mostly arguments. Just playing the Law side could be easily done.
Hmm. As I think of TV, it seems that most shows are "obvious" as to whether they fit or not. Then, it is a question if the rules can do it or if it would be fun.
Dr. Who: Okay, this is why I responded and why I said my earlier statements. The old Dr. Who RPG, by FASA, allowed supporting characters that could be as good in one subject as a Time Lord was in five or six. That, to me, made them playable. I don't think that d20 Modern, as it is, could handle this well. Also, d20 Modern isn't trying to do futuristic, which is a lot of what Dr. Who was about. For example, how do you handle the differences in technology levels? (Progress levels?

) How does a 17th century person react to 25th century tech, much less the advanced tech of the Gallifreyans? What are the rules for a 17th century person using advanced tech? Yes, a gun works about the same but what about a computer? a car?
Buffy/Angel: I think one of the problems that these type of game conversions must overcome is that there is only supposed to be one slayer or one vampire with a soul. To do that again, makes it cliched. So, the bigger question would be how to do it and allow the players to play the slayer.
To that end, I think the Buffy game itself is a very good system, giving the Slayer advantages but also making it possible to play a muggle like Xander. Buffy can do some impressive things that Xander can't do but Xander has some advantages as well in that system.
I think d20 Modern could handle it as well but I don't think there would be quite the difference in ability, without adding a template for the Chosen One. In other words, all d20 Modern characters of equal level are about the same. Therefore, it would take some special abilities, more than an advanced class that anyone can take, to really create the Chosen one. I think it can be done, but then there is the problem that the main characters would be 8th level, while the others are 4th level. That's the only way I can think of, off the top of my head, to accurately show how much better a fighter Buffy is, with a level difference. But, I don't think that d20 does that very well. Things that challenge the main character, then, could easily kill the supporting cast.
Not a bad question! Thanks!
edg
"That's just my opinion. I could be wrong." Dennis Miller