  3d lattice studies have recently attracted a lot of attention, especially in
connection with finite temperature field theories. One ingredient in these
studies is a perturbative computation of the 2-loop lattice counterterms, which
are exact in the continuum limit. We extend previous such results to SU(N)
gauge theories with Higgs fields in the fundamental and adjoint
representations. The fundamental SU(3)xSU(2) case might be relevant for the
electroweak phase transition in the MSSM, and the adjoint case for the GUT
phase transition and for QCD in the high temperature phase. We also revisit the
standard SU(2)xU(1) and U(1) theories.
