I've been to Tenerife before, but we've never stayed in Los Chritianos, we normally stay in Playa de las Americas.
In Los Christianos there is a market, welll there was one the last time I went there, but there are some many things to do in Tenerife that you won't stay in Los Christianos. You can go to Teide and if you like markets there are so many markets to choose from.
If you have a timeshare, be very careful if anyone gives you a scratch card, (you will probably win, I have won three times but we've never stayed long enough to get my prize, I won a camcorder once as well
) tell them you don't want it, its a bit of a scam.