I got a Canon 550D.
I mostly use 50mm prime f/1.8 and kit lens for portrait.
I was wondering which Flash should I buy. I am looking for a not so expensive one.
You need to figure out what you want.... If you want hot show flashes if you can go manual flash (ah la strobist) then yeah the lumopro is a good fit but if you want ettl (ah la Syl Arena) then something that can do eTTL like say a 430EX or something (sigma has some compat ones as do some cheaper Chinese companies). You could also go the studio path (say alienbee) and be happy as well... They all plus and minus aspects.
