I have almost figured out how to get one. First you have to go to Bed Bath and Beyond where they have a generic filter basket that holds a lot more coffee than the K-Cup basket. I use a Baratza Virtuoso on a 10 grind (yes that's espresso for some) setting and fill the basket to the rim, tap it down on the counter several times to pack it and then top it back off with Raw Sugar. I don't drink black coffee, gotta have some sugar and milk, and with it on top of the grounds, helps keep the Keurig from pushing all the grounds to the top and only extracting the center and actually seems to taste better than when brewing the coffee and putting the sugar in the cup. Depending on the coffee, I select either the eight or 10 ounce cup. I use this method when I just want a quick coffee and don't want to take the time to do a French press brew, and it actually makes a fairly drinkable cup of coffee. That's more than I can say for any of the pre-packed, of any brand, I've found that Keurig sells. I also leave the last couple of ounces in the cup, unless you like that taste the fines that come through the basket leaves, I don't.

Now, I know there are many of you that would not dream of brewing a cup of Keurig, but for those of us that don't know all those different flavors and just know if it's drinkable or not, then this works OK. No, it's not a cup that makes you wanna slap yo mama for not fixing you, but a lot better than anything you buy off the shelf and that quick cup at most convenience stores.

Many of my co-workers have Keurig machines and the generic filter baskets; but no grinder. I'll give this a try with pre-ground and see what they say.

I use the Eko brew refillable filters. I fill one with just under 13 gms of coffee and a coarser grind (31 or 32 on my Baratza Preciso) than I do with my Brazen, otherwise I wind up with too much sediment. I grind and fill them in the morning before I go to work.
The coffee comes out pretty good (I drink it black).

There's no way I would have time to actually brew fresh coffee (and deal with the cleanup) at work so for me the Keurig has been a great option.

I,ve tried the Ekobrew, the lids that let you reuse the Keurigs, one that has a paper filter that goes in the basket, and a couple others and my main complaint was they all seamed weak. I guess because I put sugar and milk in mine, I prefer it a lot stronger than most. I know my wife says mine is too strong for her. The generic baskets I got at BB&B are probably 1/2" taller than the K-Cup reusable baskets. I've been using those for about a year and trying different grinds and roast and found a medium roast Guat Hue, a couple degrees short of the SC and ground fine worked best for me. Then a while back I was reading how to roast and brew Cuban coffee and read how they often used raw sugar (Turbinado) on top of the grounds and how it added a different character to the cup. I gave that a try with regular sugar, and it was different. Then I tried it with Turbinado, and thought, dang this ain't bad! I've been doing this for a couple of months and just to make sure it was not just my imagination, I brewed two cups the other day, one my old way of putting sugar in afterwards and one brewing this new way. It was not my imagination, I thought this new way was a better cup.

When I get back home in a couple of weeks and can go back to using the espresso machine, I'm going to try it in it. An Americano from that is still my preferred brew.