"Best" comes with a budget. Anschutz (1416D), Winchester (Model 54), Browning (A-bolt), Sako (P94S), and others all make bolt action .22's that are many times better than either the Ruger or the Marlin - and many times more expensive.
I personally like the the CZ-452. It's a great gun for the money.
The reason why i am considering ruger and marlin is because I am on a budget. How much do the CZ's usually run for?
Looks like they have replaced the 452, with the 455 (except for the ultra-lux versions, which are spendier).
The CZ-455 Training rifle (which is the model I recommend) - has an MSRP of $375 but should sell for less.
I should mention, there is also a rifleman group here, you may get more responses within it.
Both are very good. Any out of the box 22 from an American company (note I didn't say manufactured in America) will be a safe, accurate, excellently made rifle, so get whichever fits your budget. When you buy a rifle, think backwards from the target. Pick a target, then pick a caliber to do what you want to the target, then pick sights, then pick a barrel, then pick an action, then pick a stock that fits you. Ergonomics is pretty important. Pick a rifle you can pick up and quickly get a sight picture with.
I was searching for a .22 for my kids and ended up getting a Marlin 795. Great gun and I have been happy with both Marlin firearms that I own. Like John said most of the .22 American brand rifles you get will be good guns and last a long time if you take care of them.
If you are having trouble deciding between two or three different ones then I would recommend going with the cheaper one. Take the money you saved and use that to start saving for the next firearm or put toward ammo.