Practical (and secure) PRGs
Use any DRBG (deterministic random bit generator) in the NIST FIPS (the NIST 800-90 publication series).  Except... don't use Dual EC DRBG, which has serious problems and is likely to be withdrawn.  Use any DRBG in that standard other than Dual EC DRBG.

Or, hash the seed with SHA256, then use AES256 in counter mode to generate output.

Either of those will work fine.

Don't use BBS.  It has major problems (search on this site for other examples).  There is no reason to use any of the number-theoretic PRGs in practice.