A single earner making a boatload of money in a married household has his/her taxes reduced by the switch to the "filing jointly" tax and retirement contribution thresholds, which are all higher than the single filer thresholds. That's the most common "marriage benefit" in taxes.
The "marriage penalty" is most commonly when two high-earners marry and realize that the filing-jointly cap is not double the filing-single cap - they pay more in taxes.