Your list should depend on what army you want to use - one that 'obeys' force organisation chart or one that is unbound. I've always liked a reasonable balance however. My staple list consists of at least:
- 1 Flying Daemon Prince (Close Combat/Psyker up to you)
- 2 x 10 CSM squad, nurgle, 2 x Meltagun in Rhino
- 3 Obliterators, nurgle.
Chaos Space Marines main strength is (IMO) the range of versatile infantry we have access to, T5 troops choices? Yes please. You can also 'theme' an army by taking a HQ that makes cult choices troops.
'If you fail to prepare then you'd better prepare to fail'