Most sensible browsers nowadays have a quicksearch feature, whereby you press a key (usually '/') and start typing what you want. On this page, type the number of the bus you want, space, then the first few letters of the destination.
For example, for the number 99 travelling towards Foo (I can't use real buses because that might land you in this box), I would type "/99 foo" (in Mozilla Firefox and Opera; Internet Explorer will probably never have this functionality because Microsoft is dumb) and press Enter (Where to type that: nowhere. If you must click something first, click the middle of your browser window, then just type).
Because BC Transit's website sucks and they are lazy.
Well, first I went to BC Transit's site and (labouriously) clicked my way into a schedule. They've got this table of bus routes and it just so happens that they separate destinations with a / character. This made it really easy to split by that, and then all I had to do was paste it into this cheap little spreadsheet that I made. Yay for me.