Wolfcub. Depends a bit on what you're after. Beach at Kilve is good for fossils.
Two beaches at Watchet one good for fossils, one stony with old fashioned paddling pool
Dunster beach good for walking along
Minehead beach good for sandcastle and paddling when tide in
Lynmouth beach is just over the border into Devon. Good for rock pools.
All water muddy looking as it's the channel which can be a little off putting (no different from Weston though).
Minehead beach had loads of jelly fish washed up when I was there a couple of weeks or so ago. Not known this before though.