In the common law tradition, virtually every written opinion from the Federal Circuit cites to prior precedent. I looked at the past few years of Federal Circuit decision to discover the most cited patent cases.
The following list is ranked based on citations found in Federal Circuit patent decisions that were decided January 1, 2007 - May 26, 2010. The ranking is a combined score of both (1) the number of times a case was cited and (2) the depth-of-analysis associated with the citation. I excluded non-patent cases from the list.
- Phillips v. AWH Corp., 415 F.3d 1303 (Fed.Cir. 2005).
- Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448 (Fed.Cir. 1998).
- KSR Intern. Co. v. Teleflex Inc., 127 S.Ct. 1727 (2007).
- Markman v. Westview Instruments, Inc., 52 F.3d 967 (Fed.Cir. 1995).
- Graham v. John Deere Co. of Kansas City, 86 S.Ct. 684 (1966).
- Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576 (Fed.Cir. 1996).
- In re Calmar, Inc., 854 F.2d 461 (Fed.Cir. 1988).
- Warner-Jenkinson Co., Inc. v. Hilton Davis Chemical Co., 117 S.Ct. 1040 (1997).
- MedImmune, Inc. v. Genentech, Inc., 127 S.Ct. 764 (2007).
- Christianson v. Colt Industries Operating Corp., 108 S.Ct. 2166 (1988).
- Kingsdown Medical Consultants, Ltd. v. Hollister Inc., 863 F.2d 867 (Fed.Cir. 1988).
- Rite-Hite Corp. v. Kelley Co., Inc., 56 F.3d 1538 (Fed.Cir. 1995).
- In re Seagate Technology, LLC, 497 F.3d 1360 (Fed.Cir. 2007).