FM quality is still the best (but only with a good roof aerial and decent reception) however it may be switched off as early as 2015. (Although this is deadline is looking less likely as time progresses and may be significantly delayed.) Also - depending on your local transmitter and reception - choice of stations varies.
Freeview (Virgin Media, Sky box etc) radio via an optical digital audio connection is pretty good quality, certainly better than DAB, and will usually have more station choice but not Classic FM, and there are no local stations on my Freeview. YMMV.
Internet radio quality can vary from 'pitiful' to excellent. Again, the better internet stations sound better than DAB. BBC iPlayer and live radio on the internet are excellent. Choice is vast. Around 8000 - 10,000 'stations' although I doubt anyone has tested how many are still active. Still, plenty by any measure.
DAB. Oh dear, what can I say? A protocol straight out of the Ark (MP2) and lower bit-rates than Freeview equivalents - in most cases - and rubbish 'building penetration' (even according to the BBC's own research studies) which makes a DAB roof aerial essential even assuming you get decent coverage for your post code. Uses more power than FM also.
Even a comparison using a respected DAB/FM tuner like the Denon TU1800 (fed with seperate FM and DAB optimised roof aerials) reveals DAB as 'flat' and lifeless in contrast to the same station on FM. (I have also read a report of a similar test conducted with an Arcam T32 recently with similar results.)
In your position I would say go with Freeview/Virgin/Sky via digital output into a DAC or internet radio, unless you don't mind investing in (or already have) a decent FM roof aerial and an FM tuner. I know from personal experience that an excellent, used Denon tuner can easily be picked up for £10 - £25 from an online auction site.