If you're looking for one of the best, which will last a lifetime, you'll be hard pressed to find anything better than the Wilson/Sinclair trimmer but it is expensive - but next year you'll have forgotten the cost.

RCBS, Lyman, Redding, Forster are all great trimmers - I use the Hornady which is just as good as the others - maybe better???

Most, if not all, can be adapted to use a cordless drill for ease of operation.