First programming language should be simple but not simpler. Java/C/C# has too many complexities to be first programming language for 12 years old, IMO, and carries a risk to actually turn away kids from programming. It's like teaching them how gravity works with equations involving calculus. Why do you even need a "class" keyword to create a simple program to sum first 100 numbers? You want to remove everything from a language until just bare minimum Turing complete syntax is left. Also curly braces needs to go to keep things simple.

From this perspective nothing beats BASIC. Python may come distant second. Some people have advocated Scheme but I'm not too sure because there is a quite a bit of friction involved as tasks become more complex. I'm also not in favor of drag-and-drop so called "visual" programming languages. It is extremely important to learn composibility and currently nothing seems to be better medium than text to express it. Gifted kids sure will have no problem learning programming from whatever language you give them but our goal should be eliminate as much technological friction as possible to make programming accessible to any kid who wants to learn it.