Which is the easiest of the four paths for a novice lay practitioner? In the Yuganaddha Sutta (AN 4.170), there is described the four paths stated below. Insight refers to vipassana and tranquility refers to samatha.


Development of tranquility before development of insight
Development of insight before development of tranquility
Tranquility developed in tandem with insight
Mind's restlessness concerning the Dhamma well under control (I guess this is "dry insight")


Of these four paths, which is the easiest, smoothest and most pleasant to a novice lay practitioner? And why?

Or is this question invalid, because meditation, insight and jhana is not suited to the lay practitioner?

Please provide quotes to support your answer from the Buddha's words, if possible.

I personally suspect that it is tranquility (at least the first jhana) before insight.



In this essay, Henepola Gunaratana promoted tranquility before insight:


  The Buddha is constantly seen in the suttas encouraging his disciples
  to develop jhana. The four jhanas are invariably included in the
  complete course of training laid down for disciples. ... Though a
  vehicle of dry insight can be found, indications are that this path is
  not an easy one, lacking the aid of the powerful serenity available to
  the practitioner of jhana. The way of the jhana attainer seems by
  comparison smoother and more pleasurable (A.ii,150-52).


However, Yuttadhammo Bhikkhu has a different view in this video from timestamp 9m 34s, where he said:


  Samatha meditation - these meditations exists. There's no question
  that there are meditations out there that will not lead you to
  enlightenment. They can't, because they are not focused on reality.
  They are creating an illusion in the mind. The only way that they
  could lead to enlightenment, is as I said, if you use that to gain
  insight. ... and because of the strength of the mind, you can see it
  clearer than you would have, otherwise. It's kind of taking a
  shortcut, but having to do a lot of preparation. So, not gaining
  anything (during this preparation phase), except for these nice states of peace and calm, and maybe
  some magical powers along the way, which is probably best suited for
  someone living in the forest. So, which should be first? It's
  totally up to you ... if you want to start with just vipassana, it was
  very clear that ... the Buddha gave this (vipassana) as the quickest
  way. A monk came up to the Buddha and said, "I'm old and I don't have
  a lot of time and my memory is not good, I don't want to learn a lot,
  give me the basics of the path" .....


So, there's obviously two camps out there. On one side, those who promote tranquility first like Ven. Henepola Gunaratana and Ajahn Brahm. But on the other side, you have those who promote insight alone or insight first like Ven. Yuttadhammo or S.N. Goenka.

And then there's the interesting opinion in this answer by Dhammadhatu and this answer by Andrei Volkov, which imply that attainment of Jhana through meditation is not for lay people, which is echoed by Ven. Yuttadhammo's statement that samatha meditation is "probably best suited for someone living in the forest".
The sutta was spoken by Ananda. It is not the words of the Buddha. The Buddha taught samatha &amp; vipassana are developed in tandem (MN 149; Dhp 372); as demonstrated in MN 118 (when it is properly understood). In short, given the path is the Eightfold Path with Three Trainings, how can there be a path that separates wisdom from the development of the path? 


  Any view belonging to one who has come to be like this is his right view. Any resolve, his right resolve. Any effort, his right effort.
  Any mindfulness, his right mindfulness. Any concentration, his right
  concentration: just as earlier his actions, speech, &amp; livelihood were
  already well-purified. Thus for him, having thus developed the noble
  eightfold path, the four frames of reference go to the culmination of
  their development. The four right exertions... the four bases of
  power... the five faculties... the five strengths... the seven factors
  for Awakening go to the culmination of their development. [And] for
  him these two qualities occur in tandem: tranquillity &amp; insight. MN
  149


Also, insight cannot occur without tranquility because true insight, as described in many suttas, results in dispassion (viraga). A mind with dispassion will naturally have tranquility. Wrong concentration can lead to developing some degree of tranquility, but genuine insight cannot exclude tranquility. The fact the Goenka &amp; Mahasi (Yutadhammo) paths rarely discuss tranquility shows the "insight" ("vipassana") they preach is not genuine vipassana but just a form of indoctrination. 



As for the idea of "novice lay practitioner", this is contrary to the teachings of the Buddha. For example, Sariputta &amp; Moggallana were novices yet the Buddha immediately knew they would be his chief disciples. Also, the Buddha rarely taught meditation to lay people. Most lay people do not have the conditions to develop jhana. Therefore, the questions here are not realistic. Lay people should develop morality so to avoid unnecessary problems with their lives.