Welcome Yarhead, my fellow IND flyer.

If NYC and DC are your "primary" locations do you have a preferred airport in those cities? Personally I prefer DCA and LGA which makes NW very attractive and within Skyteam you also have CO going into EWR and DL going into JFK. You can connect to your southeast US destination via ATL with DL and also via MEM via NW. West destinations, it really depends on which locations you are going to as to which carrier is best but NW has som decent direct flights to LAX etc and I would think DL would have some decent connections via SLC. So, for purely domestic flying I actually like Skyteam for the primary destinations you mention as far as which carrier you would make your primary carrier for depositing your miles it would really depend on which one of those you think you would fly the most and get the most bang for your buck. One thing I dont like so much about Skyteam is that I always seem to have to pay a $50 or $75 fee to book and award but I guess that is because I dont book like 2 weeks out etc but I dont have that situation with UA my primary carrier but DL, NW and CO seem to have decent online booking engines for not only flights but awards which is nice. Also, if you are interested in racking up some miles then you may look at DL and connecting in CVG which is only like a 20 minute flight but gives you 500 miles and is a nice airport to connect in, IMO.

As far as Star Alliance. For domestic flying I would avoid UA like the plague. I have been 1k on United for about 7 years now and most of my flying has been to asia europe etc but lately I have been doing more segments and domestic ones and you will need to go though ORD with UA and unless you take the 6AM flight from IND-ORD you will be delayed and often sit on the ground due to air traffic in Chicago. People talk about weather in Chicago being the problem but I have sat on the ground in IND for 2+ hours on multiple occasions on perfect sunny days due to weather. I had to go to MCI for like 20 weeks straight and chose UA because of my status and it was very painful....really regretted not taking the NW direct after all was said and done. As far as US, they do a good job in IND. The agents are good and have years of experience. It was better at one time when they had a club etc but still they have some pretty good people at the US gates and counters. They have some good flights to DCA and LGA but LGA is all RJ's I think and the E145's at that which can be painful even for a relatively short flight. US is also pretty cheap to the southeast portion of the country and has some decent connections via CLT. You also have connection options on US via PHX to the west.

I dont know much about Airtran but I do like Frontier but if you primary destinations are NYC and WAS then you will be conecting through ATL most of the time and again if you want miles/segements that isnt a bad thing but just doesnt appeal to me personally.

I hate Southwest so I will leave it at that on that option.

So, personally....I would be either NW or US depending on exactly where I was flying and a sampling of fares and schedules to those destinations. For me, domestic flying absolutely sucks and I dont see how some of you guys do it. I am now a 100+ segment per year flyer but couldnt imagine doing 100 segements per year purely domestic.