Is there any alt-coin that is worth mining without a rig or a strong pc?
A bit of self promotion here.
MonetaryUnit is Quark based (i.e CPU mineable) currently with a very low difficulty, so plenty of opportunity to mine blocks.
I use a single thread of my home PC to mine at idle speed (and serve the network).
Granted, the coin is not yet listed on any exchange, however there are plenty of services in the pipeline, including adding to an exchange in the future, and you would certainly be welcome .
Please have a look at the ANN and see if this is something that may appeal to you.
https://bitcointalk.org/index.php?topic=778322.msg8773507