DAMMIT, texags ate my response! (Also, see edit below too)
2nd Try:
Giraud is the king of trimmers, bar none. They make hands down the best overall model, craftsmanship, etc. Comes with the biggest price tag too, but I've never read a bad review on any Giraud product.
Gracey is more or less second place. Theirs is not nearly as robust as Giraud, but it has good reviews and by all accounts, does a good job. Not as expensive as Giraud.
Dillon makes one that adapts to a progressive press. Seems to work well, but I have no experience with it. Like the concept though. I am sure RCBS and Hornady have similar setups since they all seem to copy one another on press upgrades and concepts.
There are some single shell electric trimmers - Forstner and Hornady make one that I know of. No clue on the Forstner setup, but the Hornady one has mixed reviews on consistent length of trim and square facing.
A lot of options with hand trimmers that attach to drills:
Giraud makes a Tri-Cutter that trims, chamfers and deburs all in one step. I have one and it is a great tool. Not particularly cheap at about $100, but very good quality and it produces consistent trim lengths.
World's Finest Trimmer is another - EDIT - I was thinking of Possum Hollow trimmers, not WFT. WFT looks to be almost identical to the Giraud Tri-Way. My mistake. Gets good reviews, but given the choice and since they are nearly the same price - I defer to Giraud. Texas guy, lives in Katy I believe.
Possum Hollow Trimmer - it only trims though, doesn't chamfer or debur. I have one and really am not all that impressed with it to be honest. I sacrificed several shells to figure out what I have to do t get a square trim on it, just doesn't produce as good of results as the Giraud Tri-Cutter.
Lee makes a zip trim system that trims to length, doesn't chamfer or debur. It is consistent, but there is no adjustment capabilitiy - it trims to a specified length and that's it.
Hand trimmers are available as well - Forstner, RCBS, Hornady, Lee and I'm assuming others make basically the same thing. Miniature hand operated lathe that you set a mechanical stop on length on. Forstner has some heads that trim, chamfer and debur - they work well, but aren't cheap. Not sure about the other brands, I'm assuming they have some similar offering.
Trimming, chamfering and deburring flat out suck - worst part of reloading for me. I just don't like doing it.
My rough order of good to bad:
Giraud
Gracey
Giraud Tri-cutter
World's Finest Trimmer
Lee Zip Trim
Forstner Hand Trimmer
RCBS/Hornady/Lee hand trimmer
Everything else