From the fluff (pre primaris only) the salamanders are the most humanitarian in their outlook, viewing their role as defenders of humanity above all, while others such as dark angels view abhumans as things to be destroyed, but will otherwise do their best to protect humans. Then you get space wolves who display human traits more than the others, but actually care no more for humans than other chapters (ie. nominally protect them but will sacrifice them if required without moral issue. You then get more into the iron hands and flesh tearer ends of the spectrum of views, where humans are weak and in the way.
Thats a full gamit of views from just the loyalist. You then get renegade marines, these can be individuals, squads, companies or full chapters. These have fallen foul of imperial laws, or become disillusioned with the imperial creed. They will do what is best for... themselves, their realms (if they still hold areas), or others they owe fealty to. These have the most scope for DiY, and it is perfectly acceptable for these marines to wage war against other loyalists and still be welcome in other sectors of the imperium. Some of the chapters who sided with the renegades in the badab wars are great examples here, forced to go against the imperial forces due to oaths they had given, or initial information they recieved. Following the conflict they might serve penance before being granted full forgiveness, or just allowed on their way, exiled from that sector etc etc. and that might not mean full forgiveness, they might still be attacked on site by the loyalists chapters in the future, but the imperium as a whole doesnt view them as enemies.
Then finally you come to full blown chaos marines, these embrace the dark gods (to some extent), wish for the emperor to be cast down and the imperium shattered. They are the polar opposite to the loyalists in terms of their 'side' but equally, while more fall into the humans are weak view of the world, there is some factions that defend their human stock for reasons other than keeping their property alive. Thousand sons, some factions within word bearers and red corsairs all easily fall into these outlooks.
In terms of wider 40k factions.... all are in it for their survival, and bar very specific exceptions, all alliances between factions are temporary conveniences at best. The Tau are sometimes portrayed as 'good', but even in their earliest fluff (ie. before any major goes at grim darking them beyond their initial conception) they were sterilising factions that joined them (humans), putting controllers on others (vespid), and using others as expendable cannon fodder (kroot). They are not good, but are doing what they can to protect tau lives, and expand their own race.
The other example of 'good' is nominally the ultramarines, in that they run their 500 worlds and the quality of life there is said to be relatively high, howeever they are still by todays standards xenophobic, harsh, militarised societies that would not really pass for 'good' in a modern context. In the context of the wider 40k universe though, I'd pick there to be born over anywhere else pretty much every day of the week.