My specialist subject, I wear classic cardigans almost every day, all year round. I like a shop that does a big range of colours as I won't wear black.
Woolovers, sizing is big though, I'm an 8-10 and the XS still come up big.
Benetton. There's a big one on Oxford Street with loads in the back
Dorothy Perkins normally do some, quality not great
M&S basic cardigans. A little on the short side but good value
Gap have some merino wool ones, never pay full price, got one this week for £9. Again would say they come up big
My splurge is House of Bruar. Lovely cashmere ones in some lovely colours and fairly true to size
Lands End, wool and cotton options available. Not tried them myself as they look a little frumpy and some of the reviews mention declining quality