Okay, so you've read through the top ten reasons why your final gravity might be stuck, and it really is. Don't loose hope here are the top ten ways to fix a stuck final gravity. These can even be combined to better restart your fermentation.
1) Give the fermentor a swirl.
Try the easy things first. You might be able to squeeze a few more points out of the fermentation by gently coaxing the yeast back into suspension.
2) Move the fermentor to a warmer area.
Fermentation temperature can change attenuation by about 2%. That might be enough to get over the line from cloyings to malty.
3) Repitch with a higher attenuating yeast
For ciders and wine, champagne yeasts, such as EC-1118, will ferment simple sugars to completely dry. For beer, Safale S-04 is also a great high attenuating yeast. At this point in the fermentation the flavors have already been added by the beer yeast, so adding this second yeast will not impact the flavor much. If the fermentation has stopped significantly short of what was expected it could be caused by a combination of under pitching and under aeration. In this case mix the yeast with one quart of water and aerate well by shaking the container until there is a think foam on top of the slurry.
4) Add simple syrup.
Sometimes the yeast needs a little kick in the pants to get going. If you are adding yeast, then it's easy to add a little extra sugar to make sure the yeast starts up.
5) Add yeast nutrients.
Especially if the beer was under pitched the yeast can run out of nutrients. It takes special proteins for yeast to convert long sugar chains found in malt extract and worts generated from high mash temperatures. The yeast nutrients will give the yeast the proteins that they have depleted.
6) Add beano
Beano from your pharmacy, or amylase enzyme from your homebrew store, will break the longer sugar chains into shorter ones. So if the yeast in the fermentor cannot digest the long chains this will help them continue their job of conversion. The only problem I have heard with this is that it works too well. You may end up at 1.000. 1/2tsp is a good starting point for a 5 gallon batch.
Other ways to fix the high final gravity without restarting fermentation
7) Dilute the beer
A final gravity of 1.020 will taste pretty sweet, but if diluted to 1.015 it might not bee so bad. The hop bitterness and the flavor will also be diluted, making it a different beer, but this may make it drinkable.
8) Add hops
A little bit of bitter will balance out the maltyness. You could add a couple of ounces of hops right into the fermentor to dry hop the beer, or make a hop tea. Either boil the hops in a approximately a 1.020 wort for 30-60 minutes to get some bitterness, or steep them for about 10 minutes in water to just get the earthy flavor.
9) Add fruit
If it's already sweet, then run with it. Fruit, by itself, is sour in beer because most of the simple sugars that they contain are fermented into alcohol, so having some malty sweetness will make a beer that the lady folk will love.
10) bottle it.
If all else fails, or you decide to leave it for other reasons, change the style name. Maybe the recipe was for a Porter but now you have a Dunkel. Maybe your American Lager is a Bohemian Pilsener.