The 1999 Physics Nobel Prize was awarded to Gerardus 't Hooft and Martinus Veltman for their work toward deriving a unified framework for all the physical forces. This chart summarizes the four forces. (Source: Contemporary Physics Education Project)
Chart on Fundamental Particles and Interactions by the Contemporary Physics Education Project
Physics News Update item on the 1999 Physics Nobel Prize.
Royal Swedish Academy webpage on 1999 Physics Nobel Prize