FPSe is worth the buy.
N64oid wait until a custom rom is made with the option to overclock the cpu.
DS emu? none.
Madden & Asphalt speed up try killing apps in the background and set the connection to airplane mode. if you have the gsm version of the phone try to root it sso you can remove some bloatware or freeze the app so it wont startup upon booting the phone.
Moderm Combat 2 excellent game wish it was longer. Even if the graphics arent as beautiful as NOVA 2 the action & QTE gameplay keeps your eyes and fingers glued to the play. However the gamepad are a hit or miss, your better using the D-Pad & screen.
Its not a launcher but close to the psp xmb check out my post here:
Made My Own XMB Theme Giving It More Of A Playstation Feel
PSP games are not compatible with FPSe of N64 emu.
Best thing to optimize the play at this point in time if you have the verizon version is to check that the app has a SD option so you can move a portion to the SD, kill some apps with an app killer so they wont run in the background using up resources. Also for intense graphic games set the phone to airplane mode. If the gsm version & it has not been updated, root it and remove bloatware.