Plant meiosis gives rise to four megaspores but usually upto three of them die by apoptosis leaving only one megaspore. But they are symmetric and three of them need not die all the time as it seems [REF].
Plasmodium being a haploid organism undergoes meiosis after fusion of gametocytes. Sexual differentiation is initiated at some point during the merozoite stage (See here and also the cross references).
Chlamydomonas is also haploid during its vegetative phase, and produces four flagellated haploid gametocytes. Sexual differentiation is apparently stochastic.
Perhaps there are more examples of organisms that do not undergo asymmetric division as seen in metazoa. There may be some stochastic asymmetry which leads to differentiation of sexes in the haploid unicellular eukaryotes and apoptosis in plant megaspores; these stochastic events may happen later as well. For plasmodium this is not really known; others I am not sure of.