  The holographic principle of quantum gravity theory has been applied to the
dark energy (DE) problem, and so far three holographic DE models have been
proposed: the original holographic dark energy (HDE) model, the agegraphic dark
energy (ADE) model, and the holographic Ricci dark energy (RDE) model. In this
work, we perform the best-fit analysis on these three models, by using the
latest observational data including the Union+CFA3 sample of 397 Type Ia
supernovae (SNIa), the shift parameter of the cosmic microwave background (CMB)
given by the five-year Wilkinson Microwave Anisotropy Probe (WMAP5)
observations, and the baryon acoustic oscillation (BAO) measurement from the
Sloan Digital Sky Survey (SDSS). The analysis shows that for HDE,
$\chi_{min}^{2}=465.912$; for RDE, $\chi_{min}^{2}=483.130$; for ADE,
$\chi_{min}^{2}=481.694$. Among these models, HDE model can give the smallest
$\chi^2_{min}$. Besides, we also use the Bayesian evidence (BE) as a model
selection criterion to make a comparison. It is found that for HDE, ADE, and
RDE, $\Delta \ln \mathrm{BE}= -0.86$, -5.17, and -8.14, respectively. So, it
seems that the HDE model is more favored by the observational data.
