Autumnal Hawkbit (Leontodon autumnalis)
I am not a botanist but by applying some basic principals identification of these tough species (thistles are another one) becomes a bit easier.
Firstly, some species are more common than others and this is a good starting point because you are, statistically, more likely to see a common species than a rare one. Then, time of year and habitat play a role.
This species, Autumnal Hawkbit is very common at this time of year and can be found in all sorts of habitat but it really loves a bit of rough ground or roadside verge. It is a tall plant, often three to four feet tall (so it can't be a Dandelion!). It also has stems that branch out with a single flower on each branch.
It is a scruffy, untidy flower that likes scruffy, untidy places. A true 'weed'.