Various methods for fitting planes in the presence of outliers
Extremely fast: M-Estimator (Early stopping might not happen in all cases, which can degrade below IRLS performance)
Relatively fast: Iteratively Reweighted Least Squares (More deterministic than M-Estimator)
Medium with early termination: RANSAC
Slow: Least Median of Squares (more robust than RANSAC in the presence of noise)
Extremely fast: Theil-Sen Estimator