I upgraded the "Top Posters" addin from 1.2 to 1.5... it is under Quick Links and "Top Posters of the Month"
You can now see the top posters for an entire year if you go to Month | All. (this was actually added in v1.3)
v1.0 - Dec 09. 2006.
v1.1 - Mar 07. 2007.
-Text fields changed to menus
-Guests automatically excluded from stats
-Updated query for better compatibility with different servers
-Updated ACP settings to allow you to list available years and number of results in menus
v1.2 - May 01. 2007.
-Bug fix (post count in current month bigger than total post count for some users)
-Improved compatibility with right-to-left styles
-Some code optimizations
v1.3 - Aug 05. 2007.
-Added page navigation
-Added option to view top posters in whole year
-Added option to exclude users from stats
-Added option to exclude forums from counts
-Group membership checking works now for supplementary usergroups too
v1.4 - Aug 06. 2007.
-Fixed bug where guest posts are counted and shown as blank line in stats
-Page navigation also shown at the bottom of the page
v1.5 - Sep 15. 2007.
-Another "unknown poster" bug fix
-Fixed bug where month is switched to current one on page select
-Easier to set years (set starting year only, others are generated automatically)
-Several minor bug fixes...