£50 can get you some SERIOUSLY good wine.
Catena Nicholas Zapata, if you like Cabs but dont wanna go for Bx or Napa pricing and want a Cab that has a bit of a mix and mellowness to it, rather than some paint removing strong concentration like a young Dominus for example. It should be £50 and SUPER delicious for a steak or roast dinner.
Other than that, yeah, get Beaujolais, Fleurie if you ask me for the ultimate feminine summer wine, or Morgon for same style but more brute force and still silky. Should be 10-15 gbp.
Get some Rhone, Cotes de Ventoux is great for the price at 6-12 gbp.
Get some good Prosecco, Ferrari Brut for example is excellent.
Dessert wine, get a cheap Colheita and it will last in the fridge when opened for months. So nice for the price, 10 gbp in supermarkets if lucky.