the first 2 are regular/"passive" speakers which require an amplifier.  The second 2 are self-powered/"active" speakers with built-in amplification.

Passive vs active is not qualitative judgement, just a description of type.

So - will you buy/use an amp of some sort (preamp/power amp, or integrated amp, or receiver) for speakers such as the Polk or Wharfedale, or do you want to skip that and use the self-powered type like M-Audio and Adam?

Quality wise, I would lean towards the first 2 - since you get $300 worth of speaker quality.  The others (one could say) give you $200 worth of speaker quality, plus $100 worth of amp.