Most if not all winter cover crops probably seem tasty to
deer. They love buckwheat, although this is usually
winter-killed, so it is more of a "fall or spring" than winter
cover crop. Some people use bands of it around their yards
and fields for a trap crop for deer. One place suggested
planting sorghum around the outside of the garden to keep
deer out. I don't know how well that works.
According to this vendor, fenugreek should be easier to till
under than tall, stemmy cover crops like winter rye:
http://www.groworganic.com/item_SCL8...greek_Raw.html
Edit:
(I don't know what Fenugreek's winter kill temperature is, meaning
how cold it can get and still have it put on more growth in spring.
Do you have root knot nematodes? In Florida, for example, usually
rye or oats are recommended over vetches to avoid having the
nematodes winter over on the vetch roots.)