I'm not one of the forum lubricant experts but I do run a Bluetec 2.1L diesel in a W205 C class and have done a few oil changes myself now that the vehicle is out of warranty. I still use either approved oil or in the last change "recommended for" 229.51. You will find that most if not all of the MB 229.51 approved oils meet ACEA C3 spec.
All my fills have been 5W30, I live in a fairly temperate climate without extremes of temperature, so no real benefit on going up to 40 at the high end or down to a 0W at the low end. I've used the following oils and I really don't have any evidence from the UOA that one is better than the other; I'm a believer that if you use any of the reputable brands with a weight and specification for your vehicle and change the oil regularly you are unlikely to have problems. I've never had an lubrication related problem in over 30 years of car ownership.
- Shell Helix Ultra ECT C3 5W30 MB 229.51 Approval
- Fuchs Titan GT1 Pro Flex XTL 5W30 MB 229.51 Approval (also MB 229.52 approval)
- Fuchs Titan Race Pro C3 Ester Synthetic 5W30. ACEA C3, recommended for MB but not approved
I would like to try the Valvoline but most of their oils are over-priced here in the UK compared to EU / global brands like Fuchs, Mannol, Shell etc.
Of the oils you suggested I would run the 5W30 Mobil 1. If your car is sitting outside in well below freezing temperatures then you may benefit from a 0W30 but there will be fewer oils available that meet 229.51. Castrol Edge Professional or Titanium and Shell Helix Ultra come to mind.