I have worked with SQL Server for about 12 years. I like it and I'm not very familiar with NoSQL.
There is one exception: I have been playing with SPARQL which is a query language somewhat similar to SQL. SPARQL works with 'triple stores' which store subject, predicate, object (SPO). If you imagine a conventional SQL table, then store each individual value in a triple consisting of (primaryKey, columnName, Value) this shows how relational data can be mapped to and from triples.
SPARQL shows its power when used with DBpedia. DBpedia is an extract of wikipedia which stores all wikipedia infobox data in a giant triple store. Using SPARQL you can (in theory) extract any of the data into a tabular form, or XML, or json.
Going back to SQL Server, it would be great if Microsoft included SPARQL support as an add-on, a bit like with 'R' (I know the latest version of SQL Server has graph support but that's not SPARQL). If SQL Server supported SPARQL, it would open up all the structured Wikipedia data to queries in SQL Server.