EDZ one-piece baselayer, £50 (now superseded, £60)
Miles covered/time: 25,000/two years
What's good: Once you have worn a baselayer under leathers the days of struggling to get in and out of them are gone forever. The EDZ suit is the best I have ever used by managing to be comfortable under the leathers, stopping them rubbing and also acting as an excellent wicking layer to keep you both cooler on hot days and warmer on cooler days. You can also take a pee thanks to a zip that undoes from the bottom up. The new version has an offset zip to stop it rubbing on your neck, thumb and ankle loops and an anti-odour treatment.
What's not: The zip can rub a little at times and the Velcro on my back protector has worn a small hole in the suit at the zip after two years of almost daily use.