Upgrading to an SSD should be your first consideration. That'll make a gigantic difference if you're still on a standard HDD. I upgraded my 2008 Unibody 15" from 2GB to 4GB ram and from a 5400RPM 250GB HDD to a Crucial M4 256GB SSD. It felt like a new machine afterwards.
In terms of SSDs, I'm pretty sure the 2010 models are still only SATA-II, so max of 300MB/sec, so I would probably advise against paying extra for a "performance"-oriented SSD model such as the Intel 5xx series, as you won't see the full benefit.
For memory, I usually use Kingston or Corsair and can recommend both. Corsair have better warranties here so they're my #1 choice usually.
For SSDs, I can strongly recommend the Crucial drives, I have four of them and they've been bulletproof. I can also recommend Intel, and Samsung, though I'm slightly skeptical of Samsung's non-Pro 840 drives, as they use triple layer NAND, which may not have the same endurance, though this will be a nonissue for normal home use.
