Since you haven't specified what displacement range or style of bike you are looking at, we'll give you multiple options to choose from. 

The Royal Enfield Hunter 350 is a good option because it will be comfortable, stylish and will give you decent performance and fuel economy too. Another bike worth taking a look at is the Honda CB300F, which is a friendly naked bike that will also be comfortable and fuel-efficient. You can also take a look at the Hero Xpulse 210, which will be far the most comfortable machine of all the bikes mentioned here. 

If you want to stick to the same displacement bracket, bikes like the TVS Apache RTR 160 4V and Bajaj Pulsar N160 are the options to consider. Take a test ride of everything you're considering before making a decision.  

Since this is your first bike, starting small and approachable would be the smart way to go about it. In that same vein, we would recommend the new Yamaha XSR155 because it is a light, comfortable, fuel-efficient machine that's also reasonably exciting to use. 

If you want a larger machine, then bikes like the Honda CB300F, Bajaj Pulsar N250 and Suzuki Gixxer 250 would be good options. 

Take a test ride of everything you shortlist before you decide. 

Since you have a commute that has some highway riding, we'll recommend bikes displacing 250cc or more so you can maintain decent highway speeds without feeling the engine is strained. 

There are loads of options in your price bracket, like the Royal Enfield Hunter 350, TVS Ronin, Honda CB300F, Bajaj Pulsar N250, Hero Xpulse 210 and TVS Apache RTX 300. 

Take a test ride of all the machines you shortlist before going ahead with your purchase. 

If you want to stick to the cruiser format, we would recommend the Royal Enfield Meteor 350 (seat height: 765mm) and the Royal Enfield Goan Classic 350 (seat height: 750mm). 

Do bear in mind that these bikes - while fairly low - weigh close to 200kg, so you will need some time to adjust to their weights. If you're open to another form factor - more specifically, a sporty-looking street naked - we would steer you toward the Honda CB300F. 

That's because with its light 153kg weight and approachable 789mm seat height, it will be a very manageable bike. 

Take a test ride of everything you shortlist before making the final decision. 

Since you have had a good experience with a Honda machine, you could stick with the brand and go with the Honda CB300F. The CB300F is light, comfortable, spacious and will return decent fuel economy. If you want to switch brands, the Bajaj Pulsar N250 and the Suzuki Gixxer 250 make for good upgrade options with their smooth engines and comfortable ergonomics. 

If you don't mind staying in the same displacement range while getting a significant performance bump, the KTM 160 Duke and Yamaha MT-15 warrant consideration. With their liquid-cooled engines and light weights, these two will give you the performance step up you want without sacrificing on mileage. 

Since you have some highway usage, we would recommend something like the Bajaj Pulsar N250 or the Honda CB300F.

Both can hold a steady 80-90 kmph without their engines feeling strained. Another option you could look at is the Royal Enfield Hunter 350, if you’re open to owning an RE.

All three are good to use inside the city, although expect relatively lower fuel economy on the Hunter than the Pulsar or CB300F. 

Keeping your requirements in mind, a 250-300cc sporty commuter like the Bajaj Pulsar N250, Suzuki Gixxer 250 or Honda CB300F will be a good fit. All three have modern looks, the required fuel efficiency you desire and will strike a good balance between city and highway duties. 

Given that you want something manageable and this will be your first bike, here are a few options we recommend.

The Honda CB300F and CB300R are both lightweight, well-built, and have low seat heights. You could also check out the KTM 250 Duke or the Husqvarna Vitpilen 250. Both are mechanically identical, but they differ in styling and riding posture, the Vitpilen has a slightly taller seat than the Duke.

All these are fun and entertaining first bike with a reasonable performance ceiling to keep you interested for a long time.