Helvellyn has a great deal of character, famous for Striding Edge and Swirral Edge. The plateau is probably the best in the Lake District. Grasmoor and Pillar are perhaps more scenic, but smaller. I nearly died once, climbing up Swirral Edge in snow. The conditions were lethal and I had neither crampons, nor axe, nor experience. I heard later a woman had to be lifted off by helicopter. She was stuck, terrified, and the path is narrow so no one else could walk. I camped once at Red Tarn below. That too was adventurous. At two or three in the morning the wind funneled down from the top thrashing my tent around so I had to move downhill for protection. It's a a quick walk, up Striding and down Swirral, with great reward. I've done that many times, also the circuit where you descend Grizedale, but my favourite now is the route which includes Sheffield Pike.