Irregular conjugations

[ya-stranen.livejournal.com]

Until yesterday, I wasn't aware of the first person singular conjugations of дать and all the verbs that have that stem. I always thought it was «даю», but to my suprise, it was «дам». I was also suprised by the third person singular conjugation—«даст». Now, I know that Russian has many irregular verbs, but are there any others that are this different?