Honestly to get a killing throw odds are your going to need to get more damage and a situational grab that is every bit as difficult and typically less efficient than a USmash. The best throws as listed are a Blue BThrow and a Purple UThrow. Blue FThrow isn't bad, but must be at considerably higher %s than any of the other options to actually KO via the KO side wall, and due to the incredible recoveries of many characters in Brawl, that makes the Blue FThrow matchup and positionally specific, notably worse than the other 3 options.
For the Blue BThrow you need to be near the edge, and in the weaker position. To put yourself in this position and hope to get this grab is placing yourself in harm's way. Should you get hit your probably in a position where you'll have to recover back to the stage, a disadvantage that can lead to more damage and can be terribly inefficient. Even if you aren't hit by your opponent, any failure to get the grab leaves you in poor positioning, and odds are a number of other pikmin to go through that aren't Blue in order to get your KO.
The other option, and if your lucky not far from blue if you missed your first KO grab, is Purple UThrow. It doesn't take much time to see the trouble here, purple up grabs suffer a severely decreased range. Fortunately at the percents you'd be killing at opponents don't break out of purple grabs before you can throw them, but that short range is again leaving you waiting looking for a difficult situation and should you miss, again you have to cycle, a problem USmash doesn't encounter nearly as badly as it only needs to be wary of White pikmin.
So yes, in general a grab may be easier to achieve in normal circumstances, however in the specific circumstances required for KO throws any advantage gained in range (or even simply horizontal range in purple's case) is lost by other necessary factors. However an USmash is far less situational, very reliable after a shielded aerial, and also particularly open in many situations when your opponent is trying to recover from the ledge. Of course theres also hyphen smashing and a number of more particular approaches/setups for this move, far more openings than a grab limited to either poor positioning (which because of Oli's recovery is a bigger deal than many other characters) or average range (considering olimar is a character built around range and spacing).
Of course none of the options should be considered bad, they all KO opponents, which is the whole point, but if were going to be speaking (dangerously) in general/broad terms, then it should be a comparison of flat out risk/reward and potential for use. In such a light I would have to agree with the OP that USmash is olimar's best knock out option. At first I thought this thread somewhat pointless, but seeing the disagreement perhaps this is an important topic not everyone understands completely, making it actually one of the best threads active right now.
So in conclusion: USmash is best, learn the situations that are most reliable in leading to a hit, as well as a few tricks that can catch your opponent off guard and close the deal. The throws are not bad and should always be remembered, however going for them is a very transparent strategy and most opponents of merit will see right through your idea because of all the situational requirements that you'll take effort to insure while looking for an opening. I suggest learning to work with USmash as your primary KO move because your opponent cannot help/avoid olimar getting close and landing a move nearly as well as an opponent can avoid getting grabbed in a certain direction in a certain part of the stage or by a slow short grab. I realize people are probably going to disagree with this and my simplified arguments above, please do present your side, this is the start of some actually helpful discussion =)
-True
. I prefer uSmash or dSmash to kill someone, but spiking is also epic and I try to do it whenever I have the chance. Throws can be quite nasty as well, especially the u- and bThrow.
