with extremely low efficiency of lasers, my bets is on Sandia Z machine.

Not that these guys are in any rush to produce practical reactor as they are also mostly nuke weapons research, yet as a side effect they have been making very interesting and meaningful progress during last 15 years. The machine itself isn't for fusion research, it is for X-ray generation, and it just happens that it generates so much and so efficiently that it seems they couldn't resist and finally started trying mini Teller-Ulam :)