It will depend on each situation. For example, if we are dealing with a case of severe male infertility, conventional IVF will probably not allow viable embryos to be obtained. Therefore, in this case, ICSI will offer a better chance of success.
However, in normal situations of good quality of both gametes, both techniques will offer good results.
Suggested for you: ICSI: Intracytoplasmic Sperm Injection.