if the falco knows what he's doing, falco can win any match up.
the only problem with that is virtually every character has some sort of chain grab to death, zero to death, or extremely cheap low percentage kills they can do on falco.
examples.
marth - moderate to combo. at low percents use dair to shine to dair to shine. getting a little higher percents you can dair to utilt. also, i prefer a little more fancy and do dair to utilt to uair to dair.... i counter marths at FD(sometimes), stadium, RC, and PF.
BUT - marth can chain grab and zero to death falco, ending with a tip hit. be careful of that. a good marth will counter a good falco at FD, BF, or story probably.
fox - very easy to combo. my personal favorite matchup. use the fairly new 'waveshining' technique. dair to shine, wavedash back or forward, depending on their DI, run up and repeat. at higher percents, throw utilts and uairs into the combo. you can dash attack to shine at 70, dash attack to fsmash at 100. i counter foxes at FD or stadium.
BUT - fox can also chain grab falco. also, falco is the easiest character for fox to cheap shine kill. learn to tech them.
jiggs - difficult to combo. very annoying matchup. shoot a lot of lasers, more than normal. try to stay away and watch for the grab. as soon as you get grabbed, start DI'ing. in fact, if you feel like you're going to get grabbed, start DI'ing before you even get grabbed. she's really hard to cheap kill and combo. i usually go for a shine off the top in this match up.
CF - easy to combo. you can waveshine CF just like fox. the only difference is use more uairs and nairs instead of dairs.
BUT - CF is really good at tech following. it's sometimes better to not tech at all against him. also, his uair goes through falco's dair so don't try to come down on him. make sure you short hop everything.
falco - at a pro level, first shine wins. lol, not quite that bad i guess, but i'm not joking too much either... do the same as against fox. watch for back throws to fsmashes...
lol... any other match ups you want me to elaborate on?