links organizer has helped me save tons of time..all my trades are setup and managed in one control panel = golden.
As for blog stuff, abpsa is great. The new all in one seo plugin really takes care of all the little plugins i had before. If you make use of tags i like the plugin Click Tags, it shows are the previous tags at the bottom when i am posting so i can just click on them instead of manually typing them out again.
for sitemaps this is the best plugin imo
http://www.arnebrachhold.de/projects...aps-generator/
+ related posts is a standard plugin