I love my Making Memories 12x12 Trimmer. Not only is it a great trimmer, but the customer service is great also. Several weeks ago, I noticed that a plastic paper guide had broken on mine. I emailed the company and explained that my dh had bought my trimmer for Valentines Day in 2008 and now it was broke. I never heard back from them, but on Monday, there was a package in the mail with a replacement part, an extra magnetic ruler, a package of jumbo brad embellishments, and a package of ribbons, 6 yards in all. My sister has the same trimmer and got it before Valentine's Day last year, the grid lines started wearing off, she contacted them, and they sent her a brand new trimmer.
I, after trying so many others have to go with the Fiscars up top that Amykins is showing. It's so versitile and easy, cuts straight, lightweight to move it out of your way, if you make a mess like I do when you're scrapping. It has the fold out arm for larger measures. It's perfect!!!
I have the old gray Fiskars trimmer, love it in every way except the blade goes all over the place. I've been "test-driving" the Making Memories rotary trimmer mentioned in posts here. It's a very nice trimmer, but it just doesn't feel quite right in my hands and isn't compatible with the way I work. Hard to explain - I do a lot of free-hand trimming, especially with photos, and it's hard to see exactly where the cut is going to be if you aren't measuring. So I think I'm going to return it. A lot of people love it, though, so it might work for you, depending on how you work.
I just got the new Fiskars Premium sliding blade trimmer that TriciaH talks about, and so far I love it, it fits with my work flow like my old Fiskars trimmer, but so far it cuts perfectly straight and it's easy to see what I'm doing. The right trimmer is really a personal thing, depending on how you like to work and what feels comfortable for you, so sometimes you just have to try out a few (or half a dozen! ) different ones to find the one that works best for you.
Another Cutterpede vote here. Just love the fact that I can get different edges and scoring in addition to the usual straight line.
I agree that a trimmer is a matter of personal preference. I tried out 4 before I found the one that worked for me.