  We analyze various models for the top quark forward-backward asymmetry
($A^t_{FB}$) at the Tevatron, using the latest CDF measurements on different
$A^t_{FB}$s and the total cross section. The axigluon model in Ref. \cite{paul}
has difficulties in explaining the large rapidity dependent asymmetry and mass
dependent asymmetry simultaneously and the parameter space relevant to
$A^t_{FB}$ is ruled out by the latest dijet search at ATLAS. In contrast to
Ref. \cite{cp}, we demonstrate that the large parameter space in this model
with a $U(1)_d$ flavor symemtry is not ruled out by flavor physics. The
$t$-channel flavor-violating $Z^{\prime}$ \cite{hitoshi},
$W^{\prime}$\cite{waiyee} and diquark \cite{tim} models all have parameter
regions that satisfy different $A_{FB}$ measurements within 1 $\sigma$.
However, the heavy $Z^{\prime}$ model which can be marginally consistent with
the total cross section is severely constrained by the Tevatron direct search
of same-sign top quark pair. The diquark model suffers from too large total
cross section and is difficult to fit the $t \bar{t}$ invariant mass
distribution. The electroweak precision constraints on the $W'$ model based on
$Z'$-$Z$ mixings is estimated and the result is rather weak ($m_{Z'} > 450$
GeV). Therefore, the heavy $W^{\prime}$ model seems to give the best fit for
all the measurements. The $W^{\prime}$ model predicts the $t\bar{t}+j$ signal
from $tW^{\prime}$ production and is 10%-50% of SM $t\bar{t}$ at the 7 TeV LHC.
Such $t+j$ resonance can serve as the direct test of the $W^{\prime}$ model.
