I'm debating what to do with my current leave-outside/winter/daily commuting bike.

It started out as a Walmart Mongoose mountain bike circa 2001 but has few original parts left on it. It had the front suspension fork replaced with an equally cheap but non-suspension fork. The front wheel is nice quality after the original wheel cracked but the rear wheel is still original. The Nashbar bottom bracket replacement now appears to be even more than slightly wobbly and I'm wondering if that's contributing to the knock I hear each time I turn the pedals. The knock is new.

The chain/7-speed cassette are probably nearing the time for a replacement again and the shifting is worse than it's been in the past. The chainline has never been all that great on the bike in any event. I usually keep it in the largest chainring and shift in between the 2nd-5th gear on the cassette for around-town riding.

The V-brakes were Nashbar replacements, all brake pads are good (Koolstop salmon), all cabling was replaced in the last several years and appears to work fine. I've got a cheap but reasonably fitting saddle and there aren't any other major issues with the bike.

Overall the bike looks like junk which I like since it decreases my chances of having it stolen. I could take it back to the LBS whom I like for a 'tune-up' which I suspect will require at least a cassette and chain replacement if not a new bottom bracket. I'm not sure I'll ever get a better chainline and the derailleurs were "upgraded" from the Walmart unbranded stuff to the cheapest Shimano models which didn't seem like too much of a step-up.

If I were to look for a new/used bike I would like to spend to too much money and would prefer a bike with 26" wheels as that would allow me to reuse both of my sets of tires (Schalbe Marathon Plus & Schwalbe Marathon Winter - i.e. not cheap tires to replace with different sizes) and fenders. Grip shifters would be ideal since they're much easier to deal with when you're wearing mittens.