Sometimes I buy action figures and sometimes I have opinions about them.
If you want size comparisons for figures, here’s an explanation.

13. Transformers Titans Return Sentinel Prime
12. Transformers Masterpiece Grimlock
11. Knock-Offs: Transformers Animated Optimus Prime & Jetman Robots
10. Plastic dinosaurs
9. D-Arts Charizard (Lizardon)
8. Figma Billy Herrington
7. Robot Damashii Doraemon
6. Konami Impact Model Lagann
5. Marvel Legends Professor X
4. Transformers Revenge of the Fallen Depthcharge
3. Transformers Masterpiece Buzzsaw
2. S.H. Figuarts Shocker Combatman
1. Lego X-Wing (9493)