Nicer rhymes with:
beiser, dryser, geiser, heiser, huyser, keiser, kreiser, kyser, kysor, leiser, meiser, peiser, preiser, pricer, reiser, ryser, schmeiser, seiser, slicer, smyser, spicer, ticer, weiser, weisser, zaiser, zeiser
Nicer sounds like:
naeger, nager, najar, najera, najjar, nakahara, nancarrow, nascar, naser, nasr, nassar, nasser, naysayer, nazar, nazario, nazer, nazzaro, necessary, necker, neckwear, negara, negri, negro, neiger, nenninger, nesser, neuhauser, neuser, newcor, newshour, newswire, ngor, niagara, nicor, niger, nigeria, nigger, nigro, nihiser, nizar, nocera, noecker, nogueira, noguera, noisier, noncore, nonnemacher, nosair, nucor, nunamaker, nunemaker, nungesser, nusser, nycor