I tend to think the best setup is a combination of strobes and halogen rotators, plus a couple halogen flashers, with very minimal white lights, but I also really like a combination of LEDs and strobes. Houston police uses a Whelen Freedom with white corner strobes and red and blue LEDs, I really like the setup a lot. (Doesn't matter if the strobes are colored or white, but with colored LEDs, it's a pretty awesome setup)
IMO the best setup would be a Code 3 MX7000 with intersection strobes, outboard standard-speed rotators, inboard strobes, and a center fast-speed rotator, plus front and rear halogen flashers, and hideaway strobes in the front turn signals.
If you're looking to not use halogen rotators, go for the Whelen Edge - my preference would be for a 6-strobe, with 4 takedowns in front, 2 halogen flashers and the two corner strobes, with 4 halogen flashers and 4 strobes in the rear. (You might want to replace 2 takedowns in front with a pair of additional strobes to make a total of 8.) Code 3 also makes excellent all-strobe versions of their MX7000 and Excalibur lightbars. Federal Signal used to make an all-strobe Vista lightbar, but it was pretty weak compared to Code 3 and Whelen; they still make the JetStrobe lightbar, however, which is a very powerful strobe bar based on their classic JetSonic series.