When I had a full time job before going solo within IM - I did a lot of stuff relating to .NET such as C# and VB.NET, SQL Server etc... These days for me its Mysql (or better yet go for MariaDB) and PHP... That's server side - so for sure you'll be needing javascrip, Ajax, Jquery.... but if its all new then head straight into AngularJS as that is the bees knees!!!
Here is my opinion..... If you are looking to get a job - then hands down most commercial businesses are still tied to microsoft and .NET.... and employment wise there is more money to be made within this area...
But if you are looking for a pragmatic solution with minimizing costs then no doubt PHP is the way to go... There is no doubt in my mind that PHP is king.... I've programmed in VB.NET, C# and PHP....and for me and many others PHP rocks and rolls and does stuff that will make your mamma proud ;-)))
