Hello . Right now three platforms are best for competitive programming .

Codeforces **** Topcoder **** AtCoder

I will not ask about codeforces as its my personal favoirite . __ which is best among Topcoder and Atcoder with respect to you . Which is good for the practicing for ACM ICPC , Code Jam etc .

Your suggestions . or should i use both ? **** if anyone doesn't want to reply here he can DM me .