Word for "Hobby"?

What is the Russian equivalent of the word "Hobby"?

To give you an example, I want to say to "Studying/Learning Russian is my Hobby." As I don't study Russian full time or professionally (yet!).

I am writing to a native Russian and so am looking for a word that maybe he would use.

Thanks in advance for any help you can give.

хобби

Thank you!

That is so simple. I feel stupid now! :(

Увлечение

Studying/Learning Russian is my Hobby
Изучение Русского языка - мое любимое занятие (it's the best way)
Изучение Русского языка - мое любимое дело
Изучение Русского языка - мое хобби
Изучение Русского языка - моя слабость
Я тащусь от изучения Русского языка (It's more colloqual way then any listed above)
Меня прет когда я изучаю Русский язык
Я балдею от Русского языка
Изучать русский язык это круто!!!