In the wake of the discovery of a Higgs-like resonance near 125 GeV at the LHC, determining its properties in detail has become extremely important. The observed production and decay modes appear to be broadly consistent with those expected from a Standard Model Higgs. However, there are hints that some modes (decays to two photons in particular) may show some discrepancy with Standard Model predictions. While future data will shed light on this possibility, we explore the effects that an extended scalar sector and vector-like fermions can have on Higgs' properties. We study the sensitivity of LHC experiments and those at lower energies to scenarios where the Higgs differs from that of the Standard Model.