If Brighton is the most common way out of town for those after a 50 mile ride and the reward of nice roads, an ice cream and maybe a beer, the road to Cambridge is arguably the best.
The most common exit route through suburbia goes out via Finchley & High Barnet, before crossing the M25 at Potters Bar. From here, the riding is massively enjoyable.
After Hereford, the B152 towards Wadesmill is excellent, leading towards Barwick and the novelty of a ford crossing the River Rib near Much Hadham.
The next major waypoint on the route is the popular Bicicletta cafe in Saffron Walden, one of the top cycle cafes in the country. Their coffee & cakes are of the highest order, as are the threads and frames on display from the likes of Morvelo & Ritte which leaves you struggling not to leave without a new present for yourself. Maybe next time.
From here, you’re around 15 miles from Cambridge and the day is pretty much done. There are also a number of excellent pubs adjacent to the road with large & welcoming beer gardens which I can confirm as a good alternative to just riding the final hour in one hit.
Strava profile of the route described above (includes some extra hills in London at the start)