Board Thread:Plants vs. Zombies 2: It's About Time/@comment-17720232-20130827231116/@comment-5475030-20130830195046

peashooter: cheap, though weak...

snow pea: pretty good, though 1 per row is enough (also doubles the effect of other peashooters)

repeater: stronger, reliable

gattling pea: costly, slow, though power makes it worth it in survival

split pea: good for diggers and pogos/pole vaulters

threepeater: multi-lane goodness, but kinda expensive...

others: never played PvZ 2 

I say snow pea is the best, though repeater gets the job done. normal peashooters and getling peas are pretty good, though.