PCSX2 has gotten very good actually. A great many games are playable. How fast they go is largely dependent on your system though. Though just recently, pcsx2 team added support for more than two cpu cores, speeding up emulation a lot (for me). A 2D game with primitive 3D elements like Disgaea won't require a fast CPU at all (nor a decent GPU). Kingdom Hearts and Final Fantasy X work really well on fairly low end specs. But for games like Metal Gear Solid 3, you might need some more oomph to your rig.
I personally have a laptop, specs-
Core i7 740qm 1.7ghz (turbo boost up to 2.8ghz)
6GB DDR3 ram
Radeon 5730 1GB
Games that run really well or at very playable speeds for me-
- Kingdom Hearts 1/2 (and RE:Chain of Memories)
- Final Fantasy X
- Final Fantasy XII
- Dragon Quest VIII (with some tweaking)
- Crash Bandicoot Wrath of Cortex
- Ape Escape 2/3 (3 has more graphical glitches, but both play well)
- Ico
- Shadow of the Colossus
- Maximo
- Jak & Daxter (the first, 2 and 3 are still pretty glitchy and unoptimized)
- Sly Cooper (first one, not tested 2 or 3)
- Okami
- Rayman 2 Revolution (some minor lag on the overworld, but otherwise it's good)
Play around with speedhacks, they're a godsend. They can break games, but many of them seems to be completely safe much of the time.
I personally have a laptop, specs-
Core i7 740qm 1.7ghz (turbo boost up to 2.8ghz)
6GB DDR3 ram
Radeon 5730 1GB
Games that run really well or at very playable speeds for me-
- Kingdom Hearts 1/2 (and RE:Chain of Memories)
- Final Fantasy X
- Final Fantasy XII
- Dragon Quest VIII (with some tweaking)
- Crash Bandicoot Wrath of Cortex
- Ape Escape 2/3 (3 has more graphical glitches, but both play well)
- Ico
- Shadow of the Colossus
- Maximo
- Jak & Daxter (the first, 2 and 3 are still pretty glitchy and unoptimized)
- Sly Cooper (first one, not tested 2 or 3)
- Okami
- Rayman 2 Revolution (some minor lag on the overworld, but otherwise it's good)
Play around with speedhacks, they're a godsend. They can break games, but many of them seems to be completely safe much of the time.