slow laggy internet

First, what do you mean "I don't get the speeds I should" Are you going by some test? If its the PS3 speed test, then ignore that, even Sony says it isn't dependable. But if you notice playing games online is worst when everyone else is using the bandwidth, then you just may be reaching a saturation point. So the first step is to see how much bandwidth they are using and make sure you have enough. Gaming actually requires very little connection speed, but it does require a very stable connection of relatively low latency. Im afraid your asking a question that would normally have a very complicated answer. Are you looking to actually figure out the problem or just buy a decent router and hope for the best?

I want to fix or correct the problem. I play Call of Duty frequently on the ps3. Sometimes/often I feel I'm a half second behind everyone else. I notice it is worse when the Roku or Wii are wirelessly streaming video content.

The problem is your kind of asking a 2 ton question but I think your looking for a 1 pound answer. That isn't a comment against your ability, just a comment about the scope of this forum. Let me see if I can give some general tips.

1. First, you need to accept that no matter what you do, there will be times you where you still experience lag. Lag or latency, is inherent in all communication, its just a matter of how much. Obviously you want less lag then you can notice, but some of the elements are outside your, and even everyone's, control. That is because each game, each match, even depending the time you play adds variables. One day the server you playing on might be having a problem, or the ISP that the server is on is having a issue, or there is a issue with one of the people between your ISP and their ISP. Or it can be a issue with someone elses connection your playing against, and so on. This isn't to say the goal is unachievable, just that there is no perfect solution. All you can do is limit the effects of factors you can control. So with that said, here are factors you can control.

A. The easiest thing is if it's worst when other people are watching movies, then play your PS3 when they are not watching. While this isn't always practical or possible, it shouldn't be overlooked.

B. Make sure you have a decent router. When talking about gaming online, its very similar to gaming offline. What do you need to get high FPS in a game? Lots of memory, fast processing and good software, right? Same thing with a router, you want to look for one that has lots of RAM, a fast CPU and good firmware.  Besides that its all about build quality and different features you need. Build quality adds to the stability and life time of the router Features fulfill certain needs

C. Configure the router correctly. Just like a good computer doesn't work right out of the box, a good router needs proper configuration to fit your particular needs. Now there are some routers that make it easier, they have things like Automatic QoS that give priority to games or Netflix. Other offer the ability to restrict bandwidth on one computer and give priority to another. But in the end a tool is only as good as you use it, so tweaking the router is your best bet.

D. Make sure the connection from the PS3 to the router is good. Wired is best, but make sure the ethernet wire isn't too long and is in good shape. Easiest way to do that is to unplug it from the PS3 and plug it into a computer to run some tests.

E. Make sure the modem's signal levels are good and that the modem has a stable power source and isn't overheating. 

So with that said, if you actually want suggestions for routers, I would need to know your price range and what you require it to do. What kind of Wifi do you use? G/N/AC? Will it have a printer connected to it? What kind of range do you need? How many ethernet ports do you require? And so on.

I appreciate the responses.

Depending on how much of a difference the a newer/better router would make is going to determine how much I'm willing to spend. The one I have now is a Cisco-Linksys e1200 version 1. If you want me to throw out a number lets say $150-200. I'm pretty sure all I need is wireless g and n. My ps3 is the only thing that is hard wired and its on a 3 ft. ethernet cable, very close to the router. There will NOT be a printer connected. I understand a lil bit about the RAM and CPU speed of different routers. I think mine is listed as 32 mb. I see newer ones 100+.

I do realize online gaming will never be perfect. Call of Duty does not have dedicated servers. One person in the lobby host all the others. I'm sure that is half the problem. Likewise more can be done on my end as well.

150-200$ is more then plenty. You can get a decent N router for 60-75$. If you can afford 150-200 Asus is blowing the WiFi-N competition out of the water with the RT-N66U @ 139$   There is also a good review on it here. But check out Newegg in general, there are some pretty good routers in the 50-75$ including ones made by Asus, and if Wireless range isn't as much of a concern, might be a better option. The RT-N66U though is sitting pretty right now on the top of the Wifi-N consumer router hill. Its so popular that Bestbuy actually picked up Asus just so it could sell that router. So that means if your more comfortable buying something in a brick and mortar store then you can find the RT-N66R in most Best Buys. If you do decide to get one, make sure you update to the latest firmware before you set it up. Let me know what ever router you get and I can give you tips on the best way to configure it for gaming.

But before you buy a new router, it might be a good idea to try hooking the modem direct to PS3 and seeing what gaming is that way. No router in the world will ever make your connection better then what the modem gives, so it would give you a good idea of what your looking to achieve. And if something is not good direct to the modem, you probably want to fix that first, before you buy a new router.