The effective thesis statements from the list you provided are:
- Adopting a positive attitude can reduce stress, prevent anxiety, and help you lead a better life.
- Video games can teach important values such as teamwork, perseverance, and dedication.
- This paper will show the many ways technology can help people lead healthier lives.
These statements present a clear argument or position and indicate what the paper will discuss or support. The other statements are either too vague, merely descriptive, or lack a clear argumentative focus.