In the titration of aqueous $\mathrm{HCl}$ against aqueous ammonia (strong acid with weak base), the most suitable indicator is:

The equivalence point lies in the acidic range because $\mathrm{NH}{}_4{}^{+}$ is a weak acid. Methyl orange changes colour at about pH $3$ to $4.5$, whereas phenolphthalein ($8.3$ to $10$) would change far too late.