@Ballin4life
Pikachu always gimps Ness. (Near 100% of the time).
Mario Bros too are really good at gimping Ness and can get him.
Mario (90%) Mario's Better recovery and better air speed give him a better chance than Luigi. Luigi is about (80%)
Fox 80% (Lasers and speed) The lasers can push Ness below stage level at which Ness can only recover from an opponent's mistake.
Kirby 80% (Great recovery and if he is perfect he will usually do it, but he take a little longer than Fox to get to Ness)
Falcon (45%) He really needs to be careful because there is a moderately good chance that he might not be able to make it back on the stage or that Ness will make it back.
Yoshi 50% (He can't be that aggressive off stage due to his second jump being all he has) His eggs throwing, while good at fininishing Ness can't hit at certain angles and he really only gets one throw because an egg throw animation can only allow one between the start and end of PK thunder.
DK (70%) UpB is really good at gimping Ness, but sometimes he can't make it back if Ness is at the periphery of the sweetspot zone.
Jiggly (85%) Her aerial speed and good recover make this a really easy edgeguard.
Ness (80%) intercepting PK thunder with PK thunder usually works unless the timing is off
Link (70%) (Boomerangs until he is below stage level) whiffing one may mean Ness's recovery.
Samus (65-75%) One charged shot ends it, but if it misses or doesn't have one the uncharged shots can often get him below stage. If it doesn't he has a moderate chance of making it to the ledge.
In addition, there are ways to mitigate Ness's recovery weakness's further that I haven't mentioned such as starting PK thunder early in the air and following Ness down with it until he can sweetspot the ledge.
There is also some for error in all areas of SSB. Things like the placement of tornados on Hyrule can often aid Ness's recovery as they complicate edgeguarding him.
I am not making a case for Ness's recovery being good, but Falcon and Link have a comparable ability to recover.