Of all the ones listed so far, this is te one that is most apt to change. In my experience, Falco is the single worst match-up for Pokemon Trainer in the entire roster. The main problem being that he can CG-to-spike all three Pokemon. Like Meta Knight this is listed as all three not because all three of them are "good" choices to start with, but because they're both about equally bad.
Because of Ivysaur's weakness to early gimps and relative inability to space Falco, though, it's very likely I'll end up dropping him as a recommended starter. Charizard is also somewhat on the bubble, as well. As of now, however...
If he's played very carefully, Squirtle is the one least likely to get CGed out of the gate by Falco. His aerial speed, hydroplaning skills, and relatively safe pokes give him some buffer zone. In addition, his up tilt lock is godly against a low-percent Falco (as Reflex first demonstrated). However, if you're irresponsible and/or impatient, you're going to get shield-grabbed, CGed, and spiked. DON'T PUSH FALCO, and be very cautious against him. Because of Squirtle's diminutive size, Falco's SHDL is really not a huge concern, but be wary of it just the same.
Ivysaur brings to the table, defensively speaking, what he always does. A back air wall to space, and the threat of neutral airs and Bullet Seeds when the pressure's on. Unfortunately, SHDL kills Razor Leaf unless Falco's cornered, and Ivysaur makes a pretty fair target for a CG; even worse for the spike. The upshot is that if Falco messes up his timing, he'll eat a full Bullet Seed to the face, since it's insanely difficult to DI the first hit when you're focusing on the chain grab. However, I wouldn't count on this happening at an expert level, because realistically, a good Falco isn't going to mess up his timing once he catches you.
Charizard is pretty good against Falco when he's got the pressure on. Unfortunately, when Falco's got the momentum, it's insanely difficult to get it back. In addition, his down B is the perfect answer to Flamethrower. The upshot is that it can be baited. So if you can get Falco to incorrectly anticipate your moves, you can do a good job keeping control of the early part of this match-up.