Certainly I do not have as much time of SCN as Jürgen L and Tammy Powlas, but here’s my contribution!
I started using the SCN since a joined SAP (September 2009). My major contributions are related to the database spaces (currently I work in the SAP product support supporting databases:
Because of my contributions of the Spanish category (old SCN space), I got nominated topic leader (Announcing the SCN Topic Leaders 2011-2012) and I went to the TechEd Las Vegas 2012:
SAP TechEd 2012 Las Vegas
Where I could meet some SCN colleagues: Scott Lawley, Jeanne Carboni ,Gali Kling Schneider, Laure Cetin, Jon Reed, Kevin Grove, Tobias Hofmann, Henrique Pinto and Roland Mallmann.
I think is it really important to share:
Analysing the 2012 Summer Olympics medals with SAP Lumira
Could not find the “Generic Installation Options” in SWPM?
Do you need to check which are the columns for a particular table?
Installation guides and notes for SQL Server Netweaver based products
Top 10 viewed KBAs for SAP on SQL Server for March 2013
Configuration Parameters for SQL Server
And also follow the spaces and people (e.g. Ravi Sankar Venna blogs) you consider interesting.