  We study within the perturbative many-body $GW$ and Bethe-Salpeter approach
the low lying singlet charge-transfer excitations in molecular donor-acceptor
complexes associating benzene, naphtalene and anthracene derivatives with the
tetracyanoethylene acceptor. Our calculations demonstrate that such techniques
can reproduce the experimental data with a mean average error of 0.1-0.15 eV
for the present set of dimers, in excellent agreement with the best
time-dependent density functional studies with optimized range-separated
functionals. The present results pave the way to the study of photoinduced
charge transfer processes in photovoltaic devices with a parameter-free
\textit{ab initio} approach showing equivalent accuracy for finite and extended
systems.
