Hi. My company
http://www.ocip.comhas many routers and we use a wide variety of bits. Most of the time we try to use Amana routers. They produce an decent edge quality on plexiglass and other plastics and don't have to worry so much about damaging them since they are inexpensive. On thicker acrylic/ plexiglass or when using bits .25 or less we use Onsrud bits. They make great tooling, however cost alot more on diameters .375 and greater. It's safer to start out cheep and then play with more pricey bits.
Scott