In fan terminology, an homage is a toy that is intentionally designed to resemble an earlier (usually Generation One) toy or character, without being the exact same character. Noted examples of homages include Energon Downshift (based on Generation One Wheeljack) and Energon Shockblast (based on Generation One Shockwave).
Sometimes, homages are given different names from their predecessors if the actual rights to the name are lost via trademark murkiness, or if the name has already been applied to a non-homage toy within the same series.
Conversely, in order to protect trademarked names, Hasbro and Takara continue to use the same names over and over again, often on very different toys or very different characters within the official fiction. Since use of the term "homage" within the fandom is almost exclusively in reference to visual similarities, these name reuses alone are not considered homages.
Amusingly, Takara has given homages a new twist with "Ratchet Emergency Green", a redeco of the original Diaclone-based Ratchet toy in the color scheme of the live-action movie Ratchet, and "Ironhide Protect Black", a dual homage to the color scheme of both the toy's Diaclone incarnation and the character's live-action movie incarnation.
The following list is meant to include all more modern toys that 'visually' represent the Generation One characters. Re-uses of names without any visual relevance may be better placed on the trademark page.