Haven't tried tassimo, but I didn't really think too highly of the Keurig pods I tried. I know there is a large variety so I'm not willing to fully discount the product, but I found the espresso pod machines much more rewarding (nespresso and the nescafe dolce gusto). The variety is limited but everything tastes like coffee should when it comes out of that machine.
We use a jura-capresso espresso maker which is as convenient as a keurig for straight coffee. You fill the thing with beans, hit a button, and espresso or regular coffee comes out (we have it set to espresso and fill with espresso beans but could easy keep it set at regular coffee and use standard beans). It costs an enormous fortune but was a wedding gift; if you are wealthy beyond measure as all anandtech forum posters are known to be, then I would recommend looking into one.