I use these eliptical stones from Spyderco, they work well and aren't too pricey. With them I can handle all blade shapes, plain or serrated.
Spyderco Pro-File, Medium/Fine Stones
Now hatred is by far the longest pleasure;
Men love in haste, but they detest at leisure.
- Lord Byron (George Gordon Noel Byron), Don Juan
(canto XII, st. 6)