Swarovski crystals are the highest quality bead out there. Their patented cuts allow the most shine, and while this can be more expensive, they are definitely worth the extra few dollars. I highly recommend choosing beads from Swarovski when making your rosary or bracelet.
Pearls - for all bracelets and rosaries
Bicones - for rosaries, decade rosary bracelet, chain/link bracelet
Rounds - for all bracelets and rosaries
Rondelles - for Mini Rosary Bracelets only
Preciosa is very similar to Swarovski, but these beads don't have quite as high quality of a shine - although only professionals can tell the difference. While it's still a high quality bead, it's only plus over Swarovski is that Preciosa costs a fraction of it's competitor.