My favorite manga of all time, I on't honestly understand why people say that it gets bad after L died, I mean his death was well written and it had no asspulls whatsoever, not to mention the transition in the anime is to this very day one of the best, there no unnecessarily parts that were not needed in order for the story to end up that way, hell i even think that it gets more exciting after L dies since Light had to deal with 2 people with two different methods unlike L who was always there next to him, and at the end it was mikamki's dumb mistake that ****ed up everything, getting out of his routine and acting independently without going with the orders, not to mention light's tight schedule, the dude literary had no time to use the note at the end, all that added to mello's suicidal act basically choke light.
10/10 manga overall, the ending is bit different in the manga so you might want to check it and there are 2 one shots, so yeah, read them !