I second Titan Racing
I spent quite a bit of time in bikeshops over December looking for a 24" as Christmas gift. My son had outgrown his 20".
If you can splurge a bit, the Titan Racing Team is probably the best 24" bike on the market at relatively sane price level.
One thing that struck me when doing Christmas bike hunting is it seems like the entire industry drastically lowered the bar for what you get for your money. When I bought my son's 20" bike 3 years ago it came with hydro formed frame, internal cabling, hydrolic disks etc. For the relative same money now, you get mechanical brakes, coils spring fork etc..
