When my company was looking for 401k plans last year, one the owner's buddies pitched a plan with a 1.0% management fee, a 1.0% "guidance fee", and the underlying expense ratios of the funds. Luckily, we did not go with that plan.
I am in the process of trying to convince the owners to switch. I work for a very small company ~10 people. If anybody else works for a small company and has a low expense plan let me know who it is through!
Vanguard (managed by Acensus) and Employee Fiduciary were the least expensive 401k plans I found. In general, Vanguard is a bit more expensive at first, but once your plan passes a million dollars in assets it will be less expensive that Employee Fiduciary. My company ended up going with Vanguard.
Also, since you are at a small company, you will likely end up being the 401k manager since that typically goes to the person most interested in finance (or the person who complains the most about the crappy 401k options). It's not a lot of work, but there is a bit of paperwork.