"Choose One Only" Voting (aka. "Plurality" or "First Past the Post") is universally regarded as the single worst voting system. It works fine if and only if there are two candidates in the race, which is why it leads to a two party system.
If there more than two candidates in the race, Choose One Only Voting is extremely vulnerable to a phenomena called The Spoiler Effect. It consistently results in two party domination, and in order to avoid your vote being wasted there are very strong incentives to vote "Lesser Evil" if you aren't sure your favorite can win.