My radios have been set only to bFM for the last 10 years. The music selection is massively varied (I'm first to admit I don't like ALL of it, but at least they play a wide WIDE variety). The current affairs (The Wire) is interesting, topical, and relevant to youth and adults alike. You can download podcasts of the best bits of every days' broadcast too.
There are awesome genre-specific shows every night, The Rhythm Selection with Dubhead (tonite 9pm), Stinky Grooves, Back On The Goodfoot on Sunday afternoons (again, a very GREAT show), Border Radio etc. They have the long running and fantastic kids show, 7 - 9am Sundays, to which my kids listen regularly.
bFM also make their own advertisements, they are funny, off beat and irreverent. The horrendous advertisements on "commercial" radio are the most brain-numbing and irritating noise I am routinely exposed to. They YELL at me, and I HATE it. /rant.
Anyway, bFM is great!
<edit> And you can stream online of course too, 48kbps AAC stream sounds as good as FM transmission, IMHO.