40 vs
60
The battle of the low tiers! While one might assume that Ike vs Samus is easily in Ike's favor because Samus has no killing potential, that is clearly not the case for this matchup. Let's discuss the matchup.
Samus is one of the floatiest characters in Brawl. She jumps pretty high and her landing back on the stage is pretty slow. She is so cool, because she wears space armor (*in awe of the armor). Anyway, what can Samus do? She can charge a gun like Megaman, shoot missiles (either slow or fast), drop a mini bomb, walkoff Dair using the normal controls without fastfalling (WHAT!?!?!? RYKO?), and oh, I think we forgot something: her ZAIR! Samus also has some great projectiles as well as great juggling potential with her Uair. Her Bair is pretty powerful and her Fair has some decent range. Ike on the other hand, has his powerful, ranged aerials and his great jab game. Ike vs Samus is a pretty patient matchup for both characters. For one thing, Samus can easily force Ike to approach with her annoying projectile game. While Ike is pretty much forced to approach against a Samus, approaching her is not that easy due to Samus's excellent range with her Zair (reaches across 1/4 or 3/8 of FD if I recall).
What Ike essentially has to do is time the approach so that he doesn't get bombarded with projectiles and avoid getting hit back by Samus's Zair. I recommend that an Ike goes a ground approach against Samus, because something I forgot to mention is that Samus can use her Screw attack out of shield if Ike hits her shield with aerials. When I say ground approach, I really do mean powershielding on the way instead of charging your way through her projectiles and racking up an easy 30-50% from missiles and charged shots galore. Once you're actually in and personal with Samus, then Ike gains the advantage. Samus's ground game is pitiful and is nothing compared to Ike's. Although, you should still be wary of her Screw attack OOS as well as ridiculous grab range. What Samus essentially has over Ike though are her aerial's juggling abilities such as her Uair and her Fair. Watch out for her Dair -> Screw Attack. Offstage wise, the best thing I would advise for an Ike player is to simply at best, try to edgehog a Samus. Samus can recover notoriously low as well as stall her recovery with her Down special (the mini bomb). Samus also has her Zair to recover with so at best, edgehog. Don't even try to spike her or intercept her, because she can easily Zair edgehog your Aether and her Dair is better than yours.
Stagewise, the most obvious neutral to ban would be FD because of its flatness and her excellent projectile game here. I also highly recommend that Ikes don't go to Battlefield against a Samus, because Samus's Zair works well through platforms and her Screw attack can be abused on this stage due to the platforms hindering Ike's aerial game. A neutral I would recommend would probably be Yoshi's Island, because Samus can't apply her projectile game too much on Yoshi's Island and the huge platform in the middle doesn't help her too much for Screw Attack. Some CPs I would recommend are Rainbow Cruise if you're good at recovering there or Delfino Plaza, because throughout much of the stage shifts, she doesn't have a projectile game advantage, something that she needs over Ike. Just make sure to watch out for her spikes when the stage shifts to a water element, which is also a reason Ikes shouldn't really go to Pirate Ship against a good Samus.
Ike definitely will have to play patient against a Samus, knowing when to approach through the wall of projectiles and patiently building up damage against a Samus. She doesn't have much killing power, but Samus definitely can rack up damage pretty quickly with her projectile game, her fantastic juggling potential aerials, and her Zair. Offstage, just try to Aether as quickly as possible if you see a Samus trying to spike you to activate Super armor frames and nullifying her spike. But yeah, play patiently, and don't approach unless you're ready to. Make sure you can power shield well before you play a good Samus!