I use and have made hex boards for years. Currently I am playing with (not on just testing) the old Heroscape boards for skirmish and other simple games (e.g. The portable Wargame series by Bob Cordrey).
For me they give
a) I like simple rules and movement fits hexes very nicely - I made a SciFi aliens vs humans on one board and hand carved the hexes in foam... The rules where one page.
b) SOBH works well with hexes and has basic conversion details in the rules both 28mm and 15mm fit well
c) 15mm and smaller (I go down to 2mm or smaller) work well with the small hexes I use
d) Line of sight is clear
e) Movement is clear - just count
f) Facing is simple and hexes give you more options than square or offset squares
Drawbacks:
a) Range is always clear
b) Roads and 90deg junctions do not look right or work well
c) Rivers and roads have a tendency to zigzag
d) Buildings are rectangular and look a bit odd on hex bases. (Trees / woods look ok though)
e) Range can be a bit odd as you count longer distances
f) The area troops can fire into is dictated by the hex shape unless you want to get very awkward on how you lay this out.
A few ways to go
a) Make your own - I carved hexes into foam (not out of) and do not recommend it unless you really need to for some odd scenery.
b) Pre made foam hexes - the old Terrain Maker system from GHQ had quality problems with the edges and corners when I binned it. This may have changed.
c) A recent kickstarter for hex templates looked neat but I did not want to cut foam for weeks
d) Mats with hexes on - either cloth or the Ogre board from SJG
e) Print your own paper plans - a lot of these have hexes as an overlay in the PDF and are a simple way to start at very low cost. Some folk get them printed onto pvc banner material
f) Using hexes on card - Lost Patrol was a classic for this but have a look at
https://www.rainnstudios.com for some great examples. These are available in the UK
g) Sticking paper or card to foam board (paper both sides on 5mm foam) - I did this for a build the map game with micro tanks once
h) Heroquest tiles - expensive to buy on eBay now
I) Last and by not the least is the Hexon boards - not keen on the hills myself but most folk love them
Two other bits I've not seen but think may work are:
a) Using ply or MDF laser cut hexes (next years project for me)
b) Bigger fiam board hexes. Someone used to sell them but I cannot find a link now.
If I was starting afresh, I would get a small village from RPGnow and print it at home with the hex overlay and give it a go. OK the print cost is not low given the price of ink now but it lets you try skirmish games out first. For larger games it's simple to take a green cloth and mark out the centre of hexes (rather than the outside) using chalk and try it again at low cost.