I'm a fairly keen cyclist...understatement! I've got a few bikes including:
1. Wilier Izoard carbon road
2. Van Nicholas titanium road
3. Dolan alluminium cross
4. Giant XTC hardtail mtb
For me my most versatile bike and the one which offers best value for money has to be my cyclocross bike. It's fairly competent on the road, the only time that it starts to feel out of it's depth is when doing really long fast rides on road. I did 70 miles yesterday on it at 18mph average over some fairly hilly terrain and it was fine, I did have road tyres on rather than knobblies. The added benefit is that you can also take the thing off road on tracks and footpaths which is a blast. For commuting it would be ideal as CX wheels are fairly strong and will put up with alot.
PlanetX are doing a nice carbon cross at the moment which looks a good deal>>>