scrap the 16F84 you can't even get free samples anymore probably soon they will stop making them but it is frustrating that 99 % of beginer stuff out there is for this pic but its outdated
My opinion is: try, if you have just programmed a 16F84 or 88, the pic16F876: it's more powerful why it have got some good peripherals like an A/D converter, timers, buses.
My PIC adventure is started with 876 why it permits to make all you can make with F84 but don't requires external peripherals!
see more projects with an unique 876 or 877(like 876 but with 40pins instead of 28) **broken link removed**!
I agree with NYPD. In PIC16F, 16F88 is the best for 18 pins.
PIC16F88x series are more powerful than 87x.
Internal oscillator, internall MCLR pullup, fail safe mode monitoring.