Well it depends on the dialect..
So in the Egyptian dialect you will hear these terms quite often:
1-fokkak, فكك which means different things depending on the context but mainly "drop it", or "never mind".
2-eshtat or eshta, قشطات أو قشطةwhich means "cool".
3-tamam, تمام which means "ok".
4-b2a, بقى pronounced as "ba'a", no meaning at all.. it's just a word we insert in every freakin sentence we say!:D
5-ya3ny, يعني pronounced as "ya'ny", which means different things again depending on the context.
6-khalas mashy, خلاص ماشي this is said when you're approving something.
7- tab kowayes, طب كويس which means something like "ok that's great"
8-bgad بحد which means "seriously".