We classify all possible new U(1) x SU(2) x SU(3) multiplets that can couple to pairs of SM particles. Assuming that production of such new particles is dominated by their gauge interactions we study their signals at LHC, finding the following five main classes: i) lepto-quark 2l 2q signals; ii) di-lepton 4l signals; iii) di-quarks 4j signals, iv) heavy-lepton 2l 2V signals and v) heavy quarks 2j 2V signals, where V denotes heavy SM vectors (with W being associated to exotic fermions). In each case we outilne the most promising final states, the SM backgrounds and propose the needed searches.

24 pages, 10 figures. Typos fixed; Addendum about the capabilities of the on-going LHC run at 7 TeV