There are a great deal of deaths within the show I felt were either well timed, or timed a bit too early with a few deaths that didn't come quick enough. Touching on some of the major deaths within the show to the point of the end of season 4...
Shane: Shane's death was well timed. The build up to his death was incredible and how it happened was very unique. The way Shane went out couldn't have been better built or well timed than it was. It was probably the most well timed death in the entire show.
Lori: In my opinion, Lori's death came at just the right time. I will admit there were times I was wishing death on her during season 2 for some of the stupid things she did, but her death was well timed in season 3. How she died was also well thought out and good. Not a great deal I can say about it other than it was well creative and well timed.
T-Dog:: While I hated to see T-Dog go, his death was also well timed. It was also creative how he went out by sacrificing himself for Carol when he realized his time was up. Again, he was a character I hated to see go, but one whose death was well timed for all tense and purposes.
Sophia: I don't have an opinion on Sophia's death one way or the other because of where her death transpired. In all fairness, we don't know when exactly she died (I don't count her being killed as a walker...). Her death without a doubt made a huge impact in the show, but with the build up between Shane and Rick at the time, it's hard for me to choose whether it was well timed or not... It helped develop the plot of season 2, but outside of that didn't seem well timed...
Dale: To me, I felt like Dale's death came to early... That's probably just bias on my part because I really liked Dale for his wisdom, but it didn't seem well timed or even creatively thought out... Here we have probably the wisest man in the group, and he goes out in the middle of the night by himself when he is always otherwise making wise choices? What the heck happened to have him make that one stupid decision when a majority of his other ones were life preserving decisions? I get he's only human, but still kind of silly. His death would have been better at the time the farm was overrun so his statement about not letting the world world take him down with it when everything went south could hold true.
Andrea: Oh my gosh... If there was one person's death who couldn't come quick enough for me, it was this one... Andrea was incredibly annoying through the show in almost everything she did. She wasn't Carl-annoying, but she was darn close... How she escaped death time and time again astounds me with her careless decisions. Even when she died, she wasted (and yes, I counted) at least a minute and a half talking to Milton instead of trying to free herself! Talk about stupidity at its finest... Her death didn't come quick enough and we could have saved ourselves a lot of migraines if she had stayed put in the CDC when it went kaboom...
Hershel: I will say flat out that I think the decision to kill off Hershel was one of the poorest decisions the creators could have made... I liked Hershel a lot, and with his death, the show took a major hit... His death will/has hindered a lot of characters and takes away the somewhat light tone he brought to the group. Without him, the group is just...dark and somewhat blah... There's no morality, humorous life, or any sort of humanity within the group really anymore... Maybe I'm just perceiving things differently, but Hershel's death was huge, and probably a loss that will hurt the show from here on out... They needed Hershel in my opinion to balance out everything else that was going on...
Honorable Mentions: Two deaths that were big, but not show defining big were Milton's and Merle's. In my opinion, Merle went a bit too early. I'd rather have seen him go in the season 3 finale than when he was killed off. Milton's death though was fairly well timed. I didn't really care for his character, but how he died was unique and incredibly welcomed. THANK YOU SO MUCH FOR KILLING ANDREA!!!
Aside from those, there is only one person in the show I absolutely want to see go, and that is Carl... My gosh, Carl is the most annoying character I have ever seen in a show... He is a careless brat who doesn't think anything through. While I get that he's just a kid growing up in this post apocalyptic world, I'd love to see a teenager who is so stupid that they almost die from choices they've made and continue to make those same stupid decisions over, and over again... I swear there are times I think he's more brain dead than the walkers...
Long story short, Carl is incredibly annoying and I would be glad to see him go from the show... I know that's never going to happen, but I still want to see it happen... I'm stumped how he even made it this far... Michone said it best when she said that stupid gets you killed... And yet, despite everything Carl has done, he's still here... A mystery if I've ever seen one...