Something sensational gets your attention. It's either amazing or a little trashy — like a sensational tabloid story.
Sensational things cause quite a sensation — usually a feeling of curiosity or interest. Sensational events and sensational people keep you watching and listening. A guy juggling seven flaming bowling balls is sensational. A super popular new song is sensational. But this word does have some negative connotations, as it often describes news stories that have little merit other than their shock value. "Sexy Starlet Visits Fertility Clinic!" is a trashy kind of sensational headline.