i like guppies i think they're gorgeous if i ever have a tank spare (or get around to buying another one) i would fill it with java moss and make it look pretty and then dump as many guppies i could in to it (obviously to the safe capacity levels)
Platies are better for communities and attractive too... Guppies get nipped in communities but are beautiful. I usualy keep them in a species tank or with cories or make a guppy community tank with harlequin rasboras or realy small, peaceful fish, cories and guppies. Voted platy for you though...