Answer
Independent assortment can produce an enormous number of combinations of chromosomes (2^{n} for n chromosomes), but genetic recombination, which happens relatively rarely along the length of the chromosome, can mix maternal and paternal copies of genes on the same physical chromosome. Independent assortment can probably produce more total versions of an organisms genomes (based on 2^{n}), but genetic recombination can result in more mixing of genes on the same homolog, a kind of variation not provided by independent assortment.
Work Step by Step
To get this answer, consider first the way that diversity is generated (2^{n} for independent assortment because of how chromosomes line up in metaphase and travel to the poles/new cells in anaphase) versus relatively rare crossing over events for genetic recombination. Then see which can give more possible combinations and whether the two give genetic variety in the same way (no, they don't).