hero meets new enemy -> enemy is too strong -> seems like hero will lose -> something happens -> hero gets more powerfull -> hero beats enemy -> go back to step one.
take that, add tons of fan service and stretch it across 300 episodes and you've got Bleach.
on a more serious note:
I really enjoyed bleach at first. it is quite faithfull to the manga so that is always a plus.
the plot is actually quite interesting and the fight scenes are great and intense. alot better than Naruto IMO.
but just like Naruto, the producers became greedy and they have stretched the story far too much. after watching literally hundreds of episodes and reading the manga, this show gets painfully repetetive and the plot takes extreamly long to thicken.
basically its a great show that turned into garbage for being prolonged too much.