Generally, NFL teams prefer to build their foundations through the draft. But every year, teams have the opportunity to add additional talent in free agency. What kind of players a team signs and how much money they commit to them can have lasting effects on a franchise. Sometimes a bad free agent deal can hamstring a team into serious salary cap concerns, such as the $11.455 million franchise tag the Washington Redskins used on Brian Orakpo. Other times, a free agent can provide above-average early returns for their teams.

Here are some of the best free agent signings from 2014:

Emmanuel Sanders, WR, Denver Broncos

Denver lost receiver Eric Decker to a five-year, $36 million contract offer from the New York Jets in free agency. He had 87 receptions for 1,288 yards, and 11 touchdowns in his final season with the Broncos.

Four days later, Denver signed Sanders to a three-year deal worth about $15 million. Sanders is on pace to finish with roughly 100 catches for 1,517 yards and 10 touchdowns. So, not only is Sanders expected to outperform Decker's career year, he'll be doing it while costing the Broncos millions of dollars less.

Sanders is seventh in the NFL in receiving yards. He's racked up five 100-plus yard games so far this season, and is on pace to finish with the second highest average yards per reception rate (13.7) of his career. Seems like a quality signing to me.

Mark Sanchez, QB, Philadelphia Eagles

Sanchez didn't exactly move the needle when he was signed by the Eagles during the off-season. No one expected him to resurrect his career after a disastrous ending in New York and the infamous butt fumble.

But strange things can happen in the NFL. Eagles starting quarterback Nick Foles suffered a broken collar bone, forcing Sanchez into the spotlight. Although the sample size is limited - 534 yards, four touchdowns and two interceptions in two games - Sanchez seems to be responding well to Chip Kelly's coaching. More importantly, he's playing himself into more money as an impending free agent.

The Eagles don't expect Sanchez to take them to the promise land. But could he be slightly better than Foles, who has thrown 10 interceptions in eight games this season? It's possible.

Golden Tate, WR, Detroit Lions

The "next man up" philosophy holds strong in Detroit. Star receiver Calvin Johnson missed three games this season, and Tate stepped up to the plate in his absence.

Tate ranks fourth in the NFL with 909 receiving yards this season. Tate, even with $31.25 million deal Detroit gave him in the off-season, is exceeding expectations. The Lions are 7-2 and first place in the NFC North. Sure, the team's top-ranked defense probably has something to do with that, but it was Tate who kept this offense afloat with Johnson sidelined.

Kyle Orton, QB, Buffalo Bills

You could have the psychic ability of Professor Charles Xavier and still not have been able to predict Orton emerging as the starting quarterback for a Buffalo Bills team that is firmly in the playoff hunt. After all, the team signed him late in August as an insurance policy, should second-year starter EJ Manuel get off to a slow start.

Four games later and the former first-round pick was a first-string bench rider. Orton, meanwhile, has played steady and effective football. He has thrown 10 touchdown passes against just three interceptions, and has a 98.4 passer rating. The Bills are 3-2 in his five starts. Should the Bills make the playoffs for the first time since 1999 - the longest active streak in the NFL - Orton won't be hailed as a savior, but he will get credit for bringing a competent hand to this offense.